Cushing Syndrome of Genetic Cause

Class of hereditary, post-zygotic and somatic forms of endogenous hypercortisolism: bilateral micronodular adrenocortical disease (primary pigmented nodular adrenocortical disease, isolated or within Carney complex; PRKAR1A, PRKACA, PRKACB, PDE11A, PDE8B), bilateral macronodular adrenocortical disease (ARMC5, KDM1A, MEN1, GNAS), adrenocortical adenoma with somatic PRKACA p.Leu206Arg, McCune-Albright syndrome with neonatal Cushing syndrome, adrenocortical carcinoma in predisposition syndromes (Li-Fraumeni, Beckwith-Wiedemann, MEN1, Lynch) and Cushing disease with a genetic basis (USP8, MEN1, CDKN1B, DICER1, Lynch, CDH23, AIP)

Literature and regulatory information updated: 26 October 2026.

0. Initial Reference Table

Endogenous Cushing syndrome (CS) is the set of manifestations caused by chronic exposure to excess cortisol produced by the body itself. It is divided into forms dependent on adrenocorticotrophic hormone (ACTH), of pituitary origin (Cushing disease, CD) or ectopic origin, and ACTH-independent forms, of adrenal origin [1, 2]. The genetic cause may be constitutional (germline, transmissible), post-zygotic (mosaic, without vertical transmission) or somatic (restricted to the tumour). The first table summarises the class; the second identifies each entity.

1. Introduction

1.1 Scope and class concept

Cushing syndrome of genetic cause is not a single disease but a set of entities that share the same physiological outcome, chronic cortisol excess, and differ in the origin of the signal that produces it. In all of them the hormonal phenotype results from one of three pathways: constitutive activation of cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) signalling in adrenocortical cells; loss of tumour suppressor genes leading to clonal proliferation of secreting adrenal nodules; or proliferation of ACTH-secreting pituitary corticotroph cells. Organisation by class allows uniform treatment of bilateral micronodular disease, bilateral macronodular disease, adrenal adenoma with a somatic variant, the neonatal hypercortisolism of McCune-Albright syndrome (MAS), adrenocortical carcinoma (ACC) in cancer predisposition syndromes and Cushing disease with a genetic basis [5, 19, 24].

Carney complex (CNC), multiple endocrine neoplasia type 1 (MEN1) and MEN4, MAS, Li-Fraumeni syndrome, the Beckwith-Wiedemann spectrum (BWS), DICER1 tumour predisposition and Lynch syndrome appear here because of their relationship with hypercortisolism. This article treats hypercortisolism as the common phenotype, with the criteria for suspicion, biochemical and genetic diagnosis, treatment and surveillance specific to cortisol excess, and covers in depth isolated PPNAD, isolated micronodular disease associated with PDE11A and PDE8B, PRKACA copy gain, ARMC5- and KDM1A-associated PBMAH, adenoma with PRKACA p.Leu206Arg and USP8-associated Cushing disease.

1.2 Founding descriptions

McCune and Albright described in 1936 and 1937 the association of polyostotic fibrous dysplasia, café-au-lait macules and precocious puberty, later recognised as a syndrome of autonomous endocrine hyperfunction [63]. Bilateral macronodular hyperplasia was described by Kirschner and colleagues in 1964, in a 40-year-old woman with long-standing CS, and has received several designations over time (AIMBAD, MMAD, AIMAH, MAH, BMAH, PMAH) [5, 45]. In 1985, Carney and colleagues gathered 40 patients (16 men and 24 women) with a “complex of myxomas, spotty pigmentation and endocrine overactivity”: 29 had cardiac myxoma, 18 had PPNAD (11 with Cushing syndrome), 10 myxoid mammary fibroadenomas, 9 testicular tumours and 4 pituitary adenoma with gigantism or acromegaly; mean age at diagnosis of the first component was 18 years and 9 of the 12 deaths resulted from cardiac myxoma [64].

The Swiss family described by Schweizer-Cagianut and colleagues in 1980 and 1982 is considered the first comprehensive description of the condition: two siblings had CS due to adrenal micronodular dysplasia, an older brother had died at 5 years of atrial myxoma, and the sister’s autopsy revealed cardiac myxoma, mammary fibroadenomas with myxoid stroma and fine perioral pigmentation, which led to the proposed designation “Swiss syndrome” [29]. The acronyms NAME (naevi, atrial myxoma, myxoid neurofibromas, ephelides) and LAMB (lentigines, atrial myxoma, mucocutaneous myxomas, blue naevi) designated the same condition until the adoption of “Carney complex”, proposed by Bain in 1986, which also distinguishes it from Carney triad [29]. In 1995, Carney reconstructed the history of Minnie G., a patient seen by Harvey Cushing in 1910 and included in the 1912 monograph, and accepted that she might have had the complex; the extended family pedigree revealed no other affected individuals [29].

The term “primary pigmented nodular adrenocortical disease” was proposed in 1984 by Shenoy, Carpenter and Carney, based on four patients aged 12 to 21 years cured by adrenalectomy: the glands had reduced, normal or slightly increased weight, with multiple nodules <4 mm that were black, brown, dark green, red or yellow, lipofuscin in the enlarged cortical cells and atrophy with loss of normal zonation between the nodules [33]. Earlier familial descriptions probably concerned the same disease: four siblings with CS from adolescence and yellow cortical nodules of 0.3–1.5 cm (Arce, 1978), two siblings with bilateral micronodular hyperplasia and CS from birth (Donaldson, 1981) and two sisters in whom the disease was attributed to steroidogenesis-stimulating immunoglobulins, a hypothesis that preceded the identification of the cAMP–PKA pathway genes [33].

Before the identification of ARMC5, several families suggested a hereditary form of macronodular hyperplasia. Findlay and colleagues described in 1993 a mother and daughter with CS at 38 years; Minami and colleagues, in 1996, two Japanese siblings (the proband, aged 69, with bruising, myopathy, hypertension and cognitive decline, died of subarachnoid haemorrhage, and her brother died post-operatively), with two other siblings without a cushingoid phenotype but with enlarged adrenals and abnormal suppression with dexamethasone; Nies and colleagues, in 2002, a family with three symptomatic women and an asymptomatic obligate carrier father, with nodular hyperplasia and abnormal suppression, which led to the proposal of autosomal dominant inheritance; and Lee and colleagues, in 2005, two Asian sisters with CS at 46 and 58 years, both with meningioma, whose relationship with the adrenal disease was then left open [45]. The association between PBMAH and meningioma was later explained by ARMC5 variants (section 2.7). In the pituitary, familial CD without apparent MEN1 was described before molecular genetics in an aunt and niece from a consanguineous family (Salti and Mufarrij, 1981), in two adolescent sisters, whose authors accepted that they might represent the first generation of a MEN1 family (Swinburn and Holdaway, 1988), and in two sisters aged 38 and 40 years with a corticotroph adenoma confirmed at surgery and normal serum calcium (Gardner and colleagues, 1989) [55].

The first patient with food-dependent Cushing, described by Hamet and colleagues in 1987, was a 41-year-old man with a unilateral adrenal adenoma, hypertension, central obesity and muscle weakness of 2 years’ duration, low morning and fasting cortisol and a rise after meals; the authors attributed it to a humoral factor released by food intake [47]. In 1992, two groups independently described food-dependent Cushing in macronodular hyperplasia. Lacroix and colleagues studied a 48-year-old woman with nodular hyperplasia, undetectable ACTH, low-normal fasting cortisol and a cortisol rise of 4-fold with oral glucose, 4.8-fold with a lipid meal and 2.6-fold with a protein meal, but no response to intravenous glucose; GIP infusion increased cortisol, which led to the concept of “illicit” expression of GIP receptors in the adrenal cortex [65]. Reznik and colleagues described a 49-year-old woman with fasting cortisol of 83–207 nmol/L that rose to 455 nmol/L after a meal, UFC of 453–690 nmol/day not suppressible with high-dose dexamethasone and a 3.7-fold response to intravenous GIP; octreotide inhibited the post-prandial rise and improved the clinical picture [66]. Ectopic expression of the GIP receptor in the adrenal cortex as the mechanism was demonstrated by de Herder and colleagues (1996) and by Lebrethon and colleagues (1998) [47].

1.3 Milestones of molecular discovery

Weinstein and colleagues identified in 1991 activating variants in exon 8 of GNAS (stimulatory G-protein α subunit, Gsα) in the tissues of four patients with MAS, including the adrenals: p.Arg201His in two and p.Arg201Cys in two, with a proportion of mutated cells varying between tissues, as is characteristic of a mosaic arising early in embryogenesis [67]. In 2000, Kirschner and colleagues showed that autosomal dominant CNC was linked to 2p16 and 17q22-24 and identified variants in PRKAR1A, the gene for the RIα regulatory subunit of PKA; in a study of 54 families they detected 15 different variants in 22 (40.7%), almost all generating a premature stop codon and mRNA decay, and described CNC as “the first human disease caused by mutations of the PKA holoenzyme” [68, 69].

Genome-wide scanning of patients with adrenocortical hyperplasia without a known defect identified in 2006 loss of heterozygosity at 2q31-2q35 and variants disrupting isoform 4 of phosphodiesterase 11A (PDE11A) in three families [70]; in 2008 a variant was described in the cAMP-specific phosphodiesterase PDE8B [71]. In 2013, Assié and colleagues found ARMC5 variants in the tumours of 18 of 33 patients (55%) with macronodular hyperplasia, always with both alleles affected, one germline and the other somatic [72]. In 2014, three groups described the recurrent somatic PRKACA variant (catalytic subunit Cα of PKA) in cortisol-producing adenomas [40, 43, 73] and a germline PRKACB rearrangement was reported in a patient with CNC [74]. In 2015 somatic USP8 variants were described in corticotroph tumours [56, 75]. The role of KDM1A in GIP-dependent PBMAH was established between 2021 and 2022 [21, 76] and quantified in 2025 in a screen of 301 index cases [48]. Pituitary blastoma, an entity recognised since 2008, was identified in 2014 as a pathognomonic feature of a germline DICER1 variant [77].

1.4 Nomenclature and reclassifications

The 2022 World Health Organization (WHO) classification of adrenocortical tumours reorganised nodular disease into sporadic nodular disease, bilateral micronodular adrenocortical disease (which includes PPNAD and iMAD) and bilateral macronodular adrenocortical disease, a designation that replaces “primary bilateral macronodular adrenal hyperplasia” and recognises the germline susceptibility and the clonal nature of each nodule [4]. The term “ACTH-independent” was reconsidered because some of these glands produce ACTH by a paracrine route; “secondary BMAH” designates hyperplasia due to chronic ACTH stimulation (CD, ectopic secretion, congenital adrenal hyperplasia) [5]. Orphanet considers the codes ORPHA:189439 (PPNAD), ORPHA:189424 and ORPHA:553 obsolete and uses ORPHA:647772 for isolated PPNAD, ORPHA:647782 for iMAD and ORPHA:189427 for CS due to bilateral macronodular disease [32, 35, 44]. “Carney triad” (gastrointestinal stromal tumour, pulmonary chondroma and extra-adrenal paraganglioma) is an entity unrelated to PRKAR1A [19, 78]. OMIM keeps the classical gene-based numbering: AIMAH1 (219080) for the form with a somatic GNAS variant, AIMAH2 (615954) for ARMC5 and AIMAH3 (620990) for KDM1A; PPNAD1 (610489) for PRKAR1A, PPNAD2 (610475) for PDE11A and PPNAD3 (614190) for PDE8B [36, 37, 45]. The same series includes PPNAD4 (615830), assigned to the 19p13 copy gain containing PRKACA, which brings together in the same entry adrenal Cushing due to a somatic PRKACA variant; CNC is divided into CNC1 (160980, PRKAR1A) and CNC2 (605244, phenotype linked to 2p16 without a known molecular basis); CD due to a somatic USP8 variant corresponds to ACTH-secreting pituitary adenoma 4 (PITA4, 219090); and AIMAH3 has the synonym “food-dependent Cushing syndrome” (FDCS) [29, 30, 39, 47, 55]. AIMAH2 and AIMAH3 appear in OMIM within braces, the susceptibility notation, consistent with the need for a somatic second hit [46, 47]. The AIMAH1 entry states that 10–15% of adrenal CS results from primary bilateral adrenocortical disease and that AIMAH accounted for less than 1% of causes of endogenous CS in the 1998–2005 series, an estimate that predates the recognition of incidental forms and MACS [45]. For consistency with the clinical literature, the text uses PBMAH and BMAD as synonyms.

1.5 Operational definitions

PPNAD is an adrenocortical disease with normal-sized to enlarged glands and multiple small (<1 cm) cortical nodules pigmented by lipofuscin, surrounded by internodular atrophy, associated with adrenal Cushing and rarely with macronodules [32]. iMAD has multiple bilateral micronodules (<1 cm), generally without pigmentation or internodular atrophy, predominantly in female children and young adults [35]. PBMAH is defined by benign bilateral macronodules (>1 cm) that produce variable amounts of cortisol autonomously [44]. Cushing disease is ACTH-dependent CS due to a pituitary corticotroph adenoma [54]. Mild autonomous cortisol secretion (MACS) is defined by the European guidelines as cortisol >50 nmol/L (>1.8 µg/dL) after 1 mg dexamethasone without signs of overt CS [79]. “Primary bimorphic adrenocortical disease” designates the adrenal histology of Cushing in MAS [80].

2. Molecular Genetics and Pathophysiology

2.1 Common mechanism: the cAMP–PKA pathway in the adrenal cortex

ACTH binds to the melanocortin 2 receptor of the fasciculata cell, activates the Gsα protein and increases cAMP. The PKA holoenzyme consists of two regulatory and two catalytic subunits; cAMP binds to the regulatory subunits, which release the catalytic subunits to phosphorylate targets such as the transcription factor CREB, and the RIα regulatory subunit, encoded by PRKAR1A, acts as the brake of the system [6]. Signalling is terminated by hydrolysis of cAMP by phosphodiesterases, including PDE11A (dual specificity for cAMP and cyclic guanosine monophosphate, cGMP) and PDE8B (the highest known affinity for cAMP) [8, 9]. Any defect that increases the signal along this axis has the same final effect: proliferation of adrenocortical cells and steroidogenesis that dispenses with ACTH. Loss of RIα (PRKAR1A), gain of dosage or function of the catalytic subunit (PRKACA, PRKACB), loss of cAMP hydrolysis (PDE11A, PDE8B) and constitutive activation of Gsα (GNAS) explain most micronodular disease and cortisol-producing adenomas, whereas ARMC5 and KDM1A act through distinct mechanisms [5, 19, 40].

2.2 PRKAR1A and Carney complex

CNC results from PRKAR1A haploinsufficiency (ClinGen: sufficient evidence for haploinsufficiency, no evidence for triplosensitivity); in tumours, biallelic inactivation increases PKA signalling, and the response to cAMP is almost twice as great in CNC tumours as in non-CNC tumours [6, 19]. Germline alleles are generally null: 14 of the 15 variants in the Kirschner series generated a premature stop codon and one affected the initiation codon, with mRNA unstable through nonsense-mediated decay and absent truncated protein [69]. Sequencing detects a variant in ~60% of probands (114 of 185 families, 62%, in the Bertherat series) and in ~80% of patients with CNC and Cushing due to PPNAD; deletions and duplications explain a further ~10%, and in a series of 51 sequencing-negative patients 11 (21.6%) had 17q24.2-q24.3 deletions of 328 bp to 3 Mb, generally with a severe or unusual phenotype due to haploinsufficiency of neighbouring genes [19, 81]. About 20% of CNC families were linked to the 2p16 locus (CNC2), whose gene has not been identified [19]. Linkage to 2p16 was established by Stratakis and colleagues in 101 patients from 11 North American families, of whom 62% had cutaneous myxomas, 30% cardiac myxomas, 31% CS and 8% acromegaly; families studied later excluded both 17q and 2p16, which leaves room for a third locus, and one of the families initially assigned to 2p16 later showed linkage to 17q [30]. In tumours from patients with CNC, including carriers of a PRKAR1A variant, the 2p16 region shows cytogenetic changes in 87% of 46 samples analysed by fluorescence in situ hybridisation, mainly amplifications, indicating involvement of this region also as a somatic event [30].

Genotype–phenotype correlations have practical consequences. Isolated PPNAD (sometimes with lentigines) diagnosed before 8 years rarely has a PRKAR1A variant. The variants c.709-7_709-2del and c.1A>G p.(Met1?) are the most frequent in isolated PPNAD and the only ones with known incomplete penetrance; when expressed, they cause mild CNC, mainly PPNAD with or without lentigines. The recurrent variant c.491_492del is associated with more lentigines, cardiac myxoma and thyroid tumours; exonic variants cause more lentigines, psammomatous melanotic schwannoma, acromegaly and cardiac myxoma than intronic variants; large deletions cause more severe phenotypes [19]. GeneReviews writes the protein consequence of c.491_492del as “p.Val164ArgfsTer5”; validation in VariantValidator with the MANE transcript NM_002734.5 gives p.(Val164AspfsTer5), the notation used in this article [82]. In a São Paulo reference cohort with 18 PPNAD index cases (15 with CNC and 3 isolated), pathogenic or likely pathogenic germline PRKAR1A variants were present in 70.6% of probands, germline PRKACA duplications in two, and the somatic second hits included PRKACA duplication, a PRKAR1A frameshift deletion and loss of heterozygosity of 17q24.2; cascade screening identified 20 carriers, 8 of whom were asymptomatic with MACS [83]. A systematic review of 210 published patients with PPNAD (151 genotyped) found PRKAR1A in 79.5% [34].

Haploinsufficiency is not the only mechanism. In a series of 51 probands with CNC, 33 (65%) had a PRKAR1A variant, all with loss of allele expression except the missense NM_002734.5:c.220C>T p.(Arg74Cys) (originally described as “307C>T”, in old cDNA numbering; classified in ClinVar as of uncertain significance), found in an English family with a typical phenotype, which produces a stable protein with increased PKA activity, as do six other variants that escape mRNA decay [31, 82, 84]. The intron 6 donor-site variant (NM_002734.5:c.708+1G>T; “IVS6+1G>T” in historical nomenclature), described in a mother and son, causes skipping of exon 6 and a shorter protein that activates the pathway in the nucleus; the mother had severe disease, with lentigines, cardiac myxoma, PPNAD and toxic multinodular goitre, and died of pancreatic adenocarcinoma with liver metastases [31]. In isolated PPNAD, Groussin and colleagues identified inactivating germline PRKAR1A variants in all five patients studied, de novo in three; in an 18-year-old woman with CS, a 2.5 cm right adrenal macronodule mimicked an adenoma, and the second hit, a 16 bp deletion of the exon 4B acceptor site, was present only in that nodule [31, 33]. The c.709-7_709-2del deletion was later found in 12 unrelated families referred for CS with PPNAD, nine without a family history and only one meeting CNC criteria, and there were carrier relatives without any manifestation, the basis for the low penetrance attributed to this variant [31]. There are also somatic PRKAR1A variants in sporadic adrenocortical tumours (three cases in a 2003 series) [31]. In murine models, Prkar1a haploinsufficiency does not reproduce cardiac myxomas or pigmentation but predisposes to sarcomas and hepatocellular carcinomas; a ~50% reduction in the protein by an antisense transgene causes adrenocortical hyperplasia with corticosterone excess and loss of heterozygosity in adrenal and thyroid tumours, and the Wnt pathway is the main pathway activated in the tumours [31].

2.3 PRKACA: germline copy gain and somatic variant p.Leu206Arg

Germline 19p13 duplications including PRKACA have been described in 5 patients from 4 families with cortisol-producing adrenocortical hyperplasia, inherited in one family and de novo in another [19, 40]. Lodish and colleagues characterised 5 patients with a 19p13.2p13.12 gain including the whole gene: duplications in 3 (one sporadic and a mother–son pair) and triplications in 2 sporadic cases; the three sporadic cases had micronodular hyperplasia with bilateral adrenalectomy in early childhood, mother and son had macronodular disease in adulthood, and triplication was associated with a more severe phenotype [41]. The pathology of these 5 patients (4 men, 1 woman, 2–43 years) showed three patterns: PPNAD with extranodular atrophy, cortical hyperplasia with capsular and extracapsular micronodular hyperplasia, and adenoma; the patient with unilateral adrenalectomy maintained raised UFC [42]. A mosaic duplication with early Cushing and acral cutaneous mucinosis has also been described [7]. The copy gain is not visible on sequencing and requires chromosomal microarray or another copy-number test [7]. In the original series, the duplications were present in 5 of 35 patients with overt CS due to bilateral adrenal disease, measured 294 kb to 2.7 Mb and always included the whole gene; there were no complete PRKACA duplications in the Database of Genomic Variants or in a database of 2000 people with intellectual disability or congenital malformations, and the patients’ cells had more catalytic subunit and higher basal PKA activity, consistent with gain of function [39].

The somatic PRKACA variant is the most frequent alteration in unilateral cortisol-producing adenomas. Beuschlein and colleagues found it in 8 of 10 adenomas by exome sequencing and in 22 of 59 (37%) adenomas from patients with overt CS, but in none of 40 patients with subclinical hypercortisolism or 82 with other adrenal tumours [40]. Goh and colleagues, with exomes of 25 tumour–normal pairs, found the variant in 35% of adenomas with overt CS and showed that PRKACA, GNAS and CTNNB1 are mutually exclusive; the Leu206 residue interacts with the regulatory subunit and the substitution abolishes this binding, with increased basal PKA activity [40, 43]. In a Chinese series, the frequency was 69.2% (27 of 39) of cortisol-producing adenomas [73]. Sato and colleagues found it in 52.3% and observed that adenomas with the variant were smaller and produced more cortisol than the others [39]. Cao’s designation “L205R” corresponds to protein numbering without the initial methionine; “L206R” is the HGVS numbering. The nucleotide notation “c.617A>C” of the original publication describes the genomic strand, because the gene is on the minus strand; with the MANE transcript NM_002730.4 the correct notation is c.617T>G p.(Leu206Arg) [82]. The variant is somatic and implies no risk for relatives [7].

2.4 PRKACB

A patient with CNC had a germline rearrangement with four copies of PRKACB (catalytic subunit Cβ), with increased Cβ and PKA activity in lymphoblasts and fibroblasts [19, 74]. The alteration explains less than 1% of CNC families [85]. This germline dosage gain is distinct from the de novo PRKACB missense variants of cardioacrofacial dysplasia 2 (OMIM 619143), which are not accompanied by hypercortisolism in the available descriptions (section 2.16) [86].

2.5 PDE11A and PDE8B: susceptibility and phenotype modification

PDE11A behaves mainly as a susceptibility locus and modifier, not as a classical Mendelian gene. OMIM records PPNAD2 (610475) as AD; ClinGen has not curated the validity of the association and GenCC classifications range from “strong” to “limited” [8]. The OMIM entry rests on two different heterozygous variants in two unrelated families from the series of Horvath and colleagues; the adrenal tissue showed loss of heterozygosity at 2q31-q35, reduced protein expression, raised cyclic nucleotides and CREB phosphorylation, the same cAMP-raising mechanism as in MAS and PPNAD1 [36, 70]. PDE11A missense variants are frequent in the population: in 150 patients with CNC caused by PRKAR1A, 25.3% had PDE11A variants versus 6.8% of controls, with a suggested contribution to adrenal and testicular tumours [87]. In 334 phenotyped patients with PBMAH, deleterious PDE11A variants were present in 11.4%, independently of ARMC5, and were associated with lower UFC and midnight cortisol and fewer nodules, that is, with an attenuated form [88]. Combined silencing of PRKAR1A and PDE11A increases CRE-dependent transcription above either alone, which underpins the modifier role [8]. Rare truncating alleles behave closer to Mendelian: in the family described by Carling and colleagues, the variant c.919C>T p.(Arg307Ter) segregated over three generations with PPNAD [38] (section 10). The variants p.(Arg804His) and p.(Arg867Gly) are frequent and were found in controls and in 19% of 64 families with testicular germ cell tumours [8].

The association of PDE8B with iMAD (PPNAD3, OMIM 614190) is less firm: it rests on an inactivating germline variant in one family and on variants of predicted impact in a case–control series of adrenocortical tumours [9, 71]. The index case was a girl with CS at 2 years, enlarged adrenals on CT and pigment granules on biopsy of the nodules, with a heterozygous PDE8B missense variant; her father, obese and hypertensive, had abnormal midnight cortisol and mild adrenal hyperplasia, without diagnosed CS [37]. OMIM assigns no mode of inheritance to this entry [37]. The most robust allelic phenotype of PDE8B is autosomal dominant striatal degeneration type 1 (ADSD1, OMIM 609161): dysarthria, gait disturbance and bradykinesia without tremor and without response to levodopa, with onset in the fourth or fifth decade and symmetrical striatal lesions on MRI, described in a three-generation German family (loss-of-function variant), in a 60-year-old Portuguese woman and in a Japanese mother and son (truncating variants) [9, 89]. In the sources consulted there is no description of hypercortisolism in families with ADSD1 or of striatal disease in carriers of PPNAD3 [37, 89].

2.6 GNAS: post-zygotic mosaicism and the adrenal fetal zone

In MAS, a post-zygotic activating GNAS variant (p.Arg201His or p.Arg201Cys; more rarely at codon 227) keeps Gsα active and cAMP raised in the cells that carry it [18, 67]. The hypercortisolism of MAS originates in the adrenal fetal zone, which functions autonomously and involutes after birth, which explains the neonatal onset, the spontaneous remission of some cases and the rarity of new Cushing after the first year [18, 23]. The histology of 9 patients showed diffuse and nodular hyperplasia with cortical atrophy and apparent hyperplasia of the zona glomerulosa, reflecting the mosaic distribution of mutated and normal cells [80]. The GNAS variant is also found in cortisol-producing adenomas and in isolated PBMAH (AIMAH1, OMIM 219080) [43, 49]. Fragoso and colleagues identified the somatic variants p.(Arg201His) and p.(Arg201Ser) (NM_000516.7:c.602G>A and c.601C>A [82, 84]) in the adrenal tissue of three unrelated patients with PBMAH, absent from peripheral blood and without signs of MAS, which left open whether these cases are limited forms of MAS or isolated entities; in a series of 65 cases of ACTH-independent adrenal CS, Sato and colleagues found somatic codon 201 variants (p.Arg201His and p.Arg201Cys) in 11 (16.9%), with tumours of mean diameter 31.9 mm versus 37.7 mm without a variant [45]. In 14 sporadic PBMAH without a PRKAR1A variant, Bourdeau and colleagues observed somatic loss of heterozygosity of 2p16 in 91% of tissues and of 17q22-q24 in 73%, with total PKA activity higher than that of the normal adrenal [45]. It is accepted that the non-mosaic form of these variants is lethal in the embryo (Happle’s hypothesis, 1986), which explains the absence of convincing familial transmission of MAS; the discordances described occurred in monozygotic twins [58].

2.7 ARMC5: tumour suppressor of PBMAH

ARMC5 encodes an armadillo-repeat protein that functions as a substrate-recognition adaptor of a cullin 3-dependent E3 ubiquitin ligase (BTB-CUL3-RBX1); its substrates include the RPB1 subunit of RNA polymerase II phosphorylated at Ser5, SREBF and NRF1 [10, 20]. Inactivation impairs apoptosis and reduces steroidogenesis per cell: PBMAH is a large mass of individually inefficient cells [10, 72]. The model is two-hit: a heterozygous inactivating germline variant and a somatic second hit (loss of heterozygosity of 16p or a point variant) in each nodule; Assié and colleagues found loss of 16p in 8 of 33 patients (24%) and, in four germline carriers, different second hits in different nodules of the same gland [72]. Germline biallelic inactivation has never been described and the Armc5⁻/⁻ murine model is lethal in the embryonic period [20].

The mutational landscape published in 2025 brought together 146 different germline variants in 232 unrelated index cases: 46% missense, 45% truncating, 3% splicing, 4% in-frame and 2% large deletions, distributed throughout the gene without a hotspot; the most recurrent (protein numbering published on NM_001105247.1, identical to that of MANE NM_001105247.2, NP_001098717.1) were p.(Arg267Ter), p.(Arg619Ter), p.(Arg764Ter) and p.(Arg898Trp) [20]. Interpretation of missense variants requires care: p.(Phe14Tyr), p.(Ile170Val) and p.(Pro507Leu) are frequent polymorphisms, and p.(Pro731Arg), described in 10 index cases, has an allele frequency >0.001 and is probably benign; the authors propose the somatic second hit in the nodule as functional evidence (PS3 criterion of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology, ACMG/AMP) for 17 missense variants [20]. Germline variants are present in 20–25% of apparently sporadic PBMAH and in ~80% of familial cases [5, 20]; in 352 consecutive patients from 12 European centres the frequency was 14.8% [90] and in 301 index cases from 8 international centres 19.9% [48]. There is no evidence of a role for ARMC5 outside PBMAH (neuroendocrine tumours, hyperaldosteronism, ACC) or of malignant progression of PBMAH in carriers [20].

Carriers have more severe disease than patients without a variant: higher UFC, post-DST cortisol and midnight cortisol, more suppressed ACTH, more diabetes and arterial hypertension, larger and more nodular glands and a higher proportion of treated patients; all carriers have at least MACS [20, 90]. Truncating variants are associated with referral for overt CS in 56% versus 21% for non-truncating variants [20]. Penetrance is high but incomplete and poorly quantified, owing to rarity and late onset; affected relatives are generally younger and have attenuated disease [20]. The first series delimited the spectrum: in Assié’s, the 18 carriers (9 women) were aged 30 to 73 years, with ACTH <5–10 pg/mL, cortisol after 1 mg dexamethasone of 3.6 to 36.7 µg/dL and UFC of 37 to 1463 µg/24 h, 15 with overt CS and 3 with subclinical CS [46]. Alencar and colleagues described a large Brazilian family with PBMAH and a germline missense variant and found other variants in 5 of 21 apparently sporadic patients and in 2 of 3 families, with a somatic event in the 4 tissues available [46]. Faucz and colleagues detected germline variants in 15 of 34 patients (44.1%), half of which were predicted to be pathogenic in silico; all carriers of a variant predicted to be pathogenic had clinical CS, versus 14 of 27 (52%) of the others, which anticipated the correlation with severity and the difficulty of interpreting missense variants [46]. Gagliardi and colleagues found variants in 4 of 5 families [46]. A 2022 case combined subclinical PBMAH (germline variant NM_001105247.2:c.2436del p.(Cys813ValfsTer104) and somatic variant NM_001105247.2:c.231_265del p.(Ala78ArgfsTer13) in the nodule; the report describes the latter as “p.A77Afs*13” and as homozygous in tumour DNA) [82, 91] with hypogammaglobulinaemia and monthly recurrent herpes labialis since adolescence; after unilateral adrenalectomy, ACTH became detectable, IgG normalised at 24 months and the infections did not recur, an isolated observation that raises, without demonstrating, the hypothesis of immune involvement [46]. Germline and somatic ARMC5 alterations have been described in meningiomas, including familial ones, without systematic brain magnetic resonance imaging (MRI) studies that would allow the incidence to be estimated [5, 20].

2.8 KDM1A: GIP-dependent PBMAH

KDM1A (LSD1) encodes a histone H3K4 and H3K9 demethylase. In GIP-dependent PBMAH, the truncating germline variant is associated with somatic loss of the wild-type allele through 1p deletion, with absence of KDM1A mRNA and protein in the tissue and overexpression of the GIP receptor (GIPR), which links cortisol secretion to meals [21, 76]. In a multicentre study of 17 patients with GIP-dependent PBMAH and CS (median age 43.3 years; 15 women), all had a pathogenic or likely pathogenic germline KDM1A variant, none of 29 controls had it, and GIPR overexpression was log2 7.99 [76]. The patients came from centres in France, Canada, Italy, Greece, Belgium and the Netherlands, three of them from two families, and diagnosis required hypercortisolism with low fasting morning cortisol and ACTH and a cortisol rise >50% after a meal (or after oral glucose or GIP infusion); pharmacological inhibition or CRISPR-Cas9 inactivation of KDM1A in H295R adrenocortical cells increased GIPR, which links the gene directly to the ectopic receptor [47]. Multi-omic analysis of 36 operated PBMAH separated three groups (ARMC5 inactivation; food-dependent Cushing with ectopic GIPR; less severe phenotype) and showed that KDM1A explains ~90% of PBMAH with food-dependent Cushing, whereas ARMC5 is absent from this group [21]. In Vaczlavik’s series with food-dependent Cushing (10 women, median 43.5 years), 9 had an inactivating germline variant, including a mother and daughter, both with PBMAH and carriers of the same acceptor-site variant (NM_001009999.3:c.352-1G>A) [47, 84]. In germline screening of 301 consecutive index cases, KDM1A was present in 10 (3.3%), ARMC5 in 60 (19.9%) and no variant in 231 (76.8%); food-dependent Cushing occurred in all KDM1A carriers and in none of the other groups, and all 10 carriers were women [48]. KDM1A and ARMC5 appear to be mutually exclusive; KDM1A also predisposes to familial multiple myeloma, and adrenal histology shows myeloid or lipomatous metaplasia and >30% eosinophilic cells [5]. In Chasseloup’s first family, two men and one woman who were carriers had multiple myeloma or monoclonal gammopathy of undetermined significance without PBMAH, and two patients in Vaczlavik’s series had a personal or family history of these diseases [47]. The penetrance of PBMAH in KDM1A carriers is considered relatively low, because it requires the somatic second hit [5]. De novo missense variants in the active site of KDM1A cause a distinct neurodevelopmental disorder (OMIM 616728), not described in the same individuals [11]. This syndrome of cleft palate, psychomotor retardation and facial dysmorphism (CPRF) was described in three boys with de novo heterozygous variants (NM_001009999.3:c.2353T>C p.(Tyr785His), c.1207G>A p.(Glu403Lys) and c.1739A>G p.(Asp580Gly); the last was classified as of uncertain significance in the publication and appears in ClinVar as pathogenic or likely pathogenic), with developmental and language delay, palatal anomalies, hypotonia, downslanting palpebral fissures, prominent forehead, broad nasal bridge and widely spaced teeth [82, 84, 92]. The mechanism and inheritance differ from PBMAH: in CPRF the missense variant is constitutional and de novo, in PBMAH the germline variant is generally truncating and the phenotype requires somatic loss of the second allele [21, 92].

2.9 Aberrant receptors coupled to steroidogenesis

In PBMAH, cortisol secretion is frequently regulated by G protein-coupled receptors (GPCR) expressed ectopically or in excess. In four studies with 87 patients (52 with overt CS and 35 with mild CS), 80.5% had an aberrant response to at least one stimulus: vasopressin 53.2%, posture 44%, cisapride or metoclopramide (5-HT4 receptor) 33.8%, glucagon 27.3%, gonadotrophin-releasing hormone 16.7%, growth hormone (GH)-releasing hormone 16.7%, thyrotrophin-releasing hormone 12.1% and meal or GIP 11.5% [5]. The most frequent receptors are AVPR1A, HTR4, ADRB1 and LHCGR, often several in the same tissue; responses to β-adrenergic agonists and to vasopressin have been described in ARMC5 carriers, and the response to GIP never, which points towards KDM1A [20]. Some glands produce ACTH locally from steroidogenic cells, with autocrine or paracrine regulation [5, 93]. The descriptions that founded the concept include a 56-year-old man whose cortisol rose with upright posture and with insulin-induced hypoglycaemia, controlled with propranolol (β-adrenergic receptor); a 36-year-old woman with orthostatic hypotension in whom vasopressin stimulated cortisol, aldosterone and androgens, with an abnormal vascular response persisting after adrenalectomy; and a woman with overt CS only in pregnancy, with cortisol stimulated by LH, human chorionic gonadotrophin (hCG) and 5-HT4 agonists, in whom prolonged LH suppression with leuprorelin reversed the condition [45]. Overexpression of the 5-HT4 receptor was found in the tissue of 4 of 6 patients with PBMAH who responded to cisapride, with no variants in the receptor gene in the 2 sequenced, and a study of 6 patients found 1 or 2 abnormal receptors in all [45].

2.10 PBMAH in hereditary syndromes

Syndromic PBMAH is rare (>95% of cases are isolated) [20]. In MEN1, adrenocortical lesions occur in 20–73% of patients depending on the imaging method, mostly non-functioning; fewer than 10% hypersecrete, and among these CS is one of the most common presentations [13]. In the Groupe d'étude des Tumeurs Endocrines (GTE) database, with 715 patients, adrenal enlargement occurred in 20.4%, tumours >10 mm in 10.1% of the cohort, bilateral in 12.5% of these, with hypersecretion in 15.3% of tumours (mostly hyperaldosteronism) and ACC in 13.8% of tumours versus 1.3% in sporadic incidentalomas [94]. In a series of 67 patients, 18 (26.8%) had adrenal lesions (8 bilateral), of which 3 with benign adrenal CS and 4 carcinomas (3 functioning, 3 deaths) [95]. In an earlier series of 31 patients, 12 (37%) had adrenal enlargement, bilateral in 7, mostly without biochemical alteration of the axis; one developed a feminising carcinoma after 4 years of surveillance of mild bilateral enlargement, all 12 had a pancreatic endocrine tumour and the benign lesions retained heterozygosity at 11q13, which led the authors to interpret the adrenocortical proliferation as a secondary phenomenon and not as a two-hit MEN1 tumour [50]. A 2001 review placed adrenocortical lesions in up to 40% of patients, mostly bilateral, hyperplastic and non-functioning, with cases of hypercortisolism and hyperaldosteronism [50]. The Oxford Desk Reference gives lower frequencies (adrenocortical tumours in 5% in the MEN1 section; 20–40% in the table of cancer patterns), a difference that reflects imaging screening [78, 96]. In familial adenomatous polyposis (APC), adrenal involvement occurs in 16% (48 of 311), bilateral in 23% of these, and PBMAH with biallelic APC inactivation has been described; PBMAH has also been described in hereditary leiomyomatosis and renal cell carcinoma (FH) [5, 20].

2.11 Cushing disease with a genetic basis

Corticotroph tumours are predominantly sporadic and monoclonal, with abundant expression of the epidermal growth factor receptor (EGFR) [24]. Somatic gain-of-function variants of USP8, an endosomal deubiquitinase, cluster in the 14-3-3 protein-binding motif (residues 718–720), reduce this binding, increase cleavage and activity of the enzyme, decrease EGFR degradation and increase POMC transcription [12, 75]. Reincke and colleagues found them in 4 of 10 corticotroph tumours by exome [75]; in a multicentre series of 145 patients, they were present in 48 of 134 functioning adenomas (36%) and in none of 11 silent adenomas, with 41% in adults versus 17% in children, 43% in women versus 17% in men, age at diagnosis 36 versus 44 years and tumours of 10 ± 7 mm [56]. The Pituitary Society consensus gives a frequency of 36–60% and states that USP8 status may predict recurrence and response to pasireotide [24]. In a Chinese series, Ma and colleagues found somatic USP8 variants in 8 of 12 corticotroph tumours by exome and in 67 of 108 (62%) in validation, versus none of 150 adenomas of other types; three recurrent exon 14 variants accounted for more than 77%, there were no germline variants, the frequency was 67.7% in women versus 38.1% in men, tumours with a variant were small and diffuse in the sella and those without a variant larger and with parasellar extension, and the rate and time to recurrence did not differ by USP8 status [55]. The variation between 36% and 62% reflects the series and methods [55, 56]. The resistance of corticotroph tumours to glucocorticoid feedback is also related to loss or mislocalisation of BRG1 or HDAC2, required for repression of POMC by the glucocorticoid receptor, observed in 17 of 36 adenomas (47%) [55]. Somatic variants of NR3C1, BRAF, USP48 or TP53 are rare [24]. A germline USP8 variant is exceptional: a girl with CD diagnosed at 14 years and recurrent, developmental delay, dysmorphism, ichthyosiform hyperkeratosis, chronic lung and kidney disease, dilated cardiomyopathy, previous hyperinsulinism and partial GH deficiency had the de novo variant c.2155T>C p.(Ser719Pro) in blood and tumour [97]; a de novo germline 22 kb deletion including the hotspot was described in a child with severe developmental delay and multiorgan dysfunction, without mention of CD in the abstract [98].

Among hereditary syndromes, MEN1 is associated with pituitary adenomas in 30–40% of patients, of which ACTH-secreting adenomas are <5%; four children aged 11–13 years had CD as the first manifestation, and there are plurihormonal adenomas and thymic carcinoids with ectopic ACTH secretion [13]. In a Franco-Belgian series of 324 patients, pituitary disease occurred in 42%, with a mean age at onset of 38 years (12–83), more in women (50% versus 31%), in 85% as a macroadenoma and with normalisation of hypersecretion after treatment in only 42% of secreting adenomas [50]. CS is more frequent in patients with Zollinger-Ellison syndrome than was assumed (8% in one series): 3 of 16 patients with this syndrome and MEN1 had CD, whereas in sporadic cases CS resulted from ectopic ACTH secretion by the gastrinoma, one of the factors associated with gastrinoma-related death in a cohort of 212 patients followed for a mean of 13.8 years [50]. CD has been described in a mother and daughter with MEN1 and discordance in 25-year-old monozygotic twins, only one of whom had CD [50]. In MEN4 (CDKN1B), pituitary tumours are the second most frequent manifestation and ACTH-secreting tumours the most common, and a mainly paediatric series of CD found CDKN1B variants in up to 2.6% [14, 53]. The French PNDS places CD in 1–2.5% of MEN1 carriers, more rarely in MEN4 and even more rarely in CNC, notes that in children it may be the first manifestation of these syndromes and also associates it with germline AIP variants, in adults and children, being present in 2.6–16% of familial isolated pituitary adenomas [22]. The first patient with MEN4 and a corticotroph tumour, a Dutch woman without a family history, had in her fifth decade an ACTH-secreting pituitary adenoma, small-cell neuroendocrine carcinoma of the cervix and hyperparathyroidism; in cohorts of patients with an MEN phenotype without a MEN1 variant, CDKN1B explained 1 of 37, 1 of 27 (3.7%), 1 of 15 and 1 of 25 cases [52]. Pituitary blastoma, a tumour of early infancy presenting with Cushing, ophthalmoplegia or diabetes insipidus and raised ACTH, had a germline DICER1 variant in 9 of 10 infants and a second hit in 9 of 10 tumours, mainly in the RNase IIIb domain [15, 77]. In Lynch syndrome, pituitary disease has low penetrance and includes ACTH-secreting macroadenomas [85]; a 51-year-old man with an MSH2 variant, colon carcinoma and severe CD had a corticotroph carcinoma with concordant loss of repair proteins, and in the Swedish cohort of 910 carriers there were 3 clinically relevant pituitary tumours versus 1 expected [99]. CDH23 (PITA5, OMIM 617540) has been associated with familial and sporadic pituitary adenomas, including ACTH-secreting tumours among the sporadic ones, in a single Chinese study without replication in other cohorts [13, 85, 100]. In that study, four families had GH-secreting and non-functioning adenomas with transmission compatible with autosomal dominant inheritance with incomplete or age-dependent penetrance; in the exome of 125 patients with sporadic adenoma, 15 (12.0%) had CDH23 variants (13 heterozygous and 2 homozygous), 4 of them with ACTH-secreting tumours, versus 2 of 260 controls (0.8%); tumours with a variant were smaller and less invasive, and the variants, in the extracellular cadherin domains, had no functional study [101]. AIP variants do not appear to increase the risk of corticotroph tumour: only one mixed ACTH/prolactin tumour with a loss-of-function variant has been described [85]. The 2021 consensus includes MEN1, RET, AIP, PRKAR1A, CDKN1B, DICER1, SDHx and CABLES1 among the genes that may predispose to paediatric CD [24, 102].

2.12 Adrenocortical carcinoma in predisposition syndromes

ACC is one of the five core cancers of Li-Fraumeni syndrome and occurs in 6–13% of TP53 variant carriers, mainly in childhood and, in adults, typically before 40 years [16]. Among children with ACC, 50–90% have a germline TP53 variant; among adults, up to 5% have TP53 and ~3% Lynch syndrome [25]. The founder variant p.(Arg337His) (NM_000546.6:c.1010G>A), frequent in South and Southeast Brazil, confers a high risk of paediatric ACC with a lower risk of other cancers: ACC accounted for 55% of childhood cancers and 23% of adult cancers in one series, with maternal inheritance in 72% [16]. The penetrance of paediatric adrenocortical tumour was estimated at 9.9% (95% CI 8.7–11.1%) in 30 families from South Brazil, with a common haplotype indicating a founder effect [103, 104]. In BWS, adrenocortical cytomegaly is pathognomonic and ACC is among the embryonal tumours, with a risk of 1.1% in paternal uniparental disomy [17]. ACC has also been described in MEN1, familial adenomatous polyposis and CNC [25]. About 50–60% of ACC show hormone excess, frequently cortisol [26].

2.13 Neurofibromatosis type 1: chance association

Reference sources on neurofibromatosis type 1 (NF1) do not include CS among its manifestations; the only adrenal endocrinopathy described is phaeochromocytoma, in fewer than 1% of adults [60]. There are two published cases: a 64-year-old man with CS due to ectopic ACTH, with ACTH precursors of 126 pmol/L, attributed to a retroperitoneal plexiform neurofibroma with transformation into a malignant peripheral nerve sheath tumour, with biochemical resolution after imatinib [61]; and a patient with macronodular hyperplasia and ACTH-independent hypercortisolism with loss of the wild-type NF1 allele in the tissue, accompanied by a murine model with enlarged adrenals and corticosterone excess [62]. Class reviews do not include NF1 among the causes of CS, and the relationship should be read as a rare association, with no indication for screening for hypercortisolism in constitutional or segmental NF1 [5, 20].

2.14 Table of the types in the class

LCCSCT: large-cell calcifying Sertoli cell tumour.

2.15 Normalised variants

All conversions were confirmed in VariantValidator with MANE Select transcripts and GRCh38 [82]. The USP8 variants p.(Ser718Pro) and p.(Pro720Leu) and the GNAS variant p.(Gln227Arg) are examples of the MANE notation of the protein change and do not reproduce the c. notation of a publication.

The reference MANE transcripts are NM_001105247.2 for ARMC5 (the 2025 mutational landscape used NM_001105247.1), NM_001009999.3 for KDM1A, NM_016953.4 for PDE11A, NM_001370259.2 for MEN1 and NM_002730.4 for PRKACA [20, 82].

2.16 Penetrance, expressivity and allelic disorders

The penetrance of CNC is >95% by 50 years, but the expression of PPNAD with Cushing is variable: it occurs in 70% of affected women before 45 years and in 45% of men, and histological evidence of PPNAD is present in almost all patients at autopsy [19]. The French PNDS gives PPNAD in ~60% of patients with CNC, isolated PPNAD, without other manifestations of the complex, in ~12% and a PRKAR1A variant in more than 70% of CNC; the difference from the GeneReviews frequencies depends on whether PPNAD with Cushing or histological PPNAD is counted and on the origin of the series (section 7.17) [19, 22]. The same protocol mentions paediatric cases of CS due to micronodular or macronodular hyperplasia in BWS, in PRKACA copy gain and with a PDE8B variant, and isolated PBMAH in adults with PRKACA amplification [22]. In the susceptibility forms (PDE11A, KDM1A) and in ARMC5 PBMAH, penetrance is incomplete and depends on somatic second hits [5, 20]. The same genes cause allelic disorders without hypercortisolism, whose confusion leads to interpretation errors: acrodysostosis type 1 due to PRKAR1A variants in the cAMP-binding domains, with hormone resistance (the opposite effect to CNC); cardioacrofacial dysplasia 1 (OMIM 619142) due to the germline PRKACA variant p.Gly137Arg (three families with postaxial polydactyly, brachydactyly, short limbs, atrioventricular septal defects or common atrium and facial dysmorphism; in one index case the variant was mosaic, with an allele fraction of 0.28, and was transmitted to the children, and in another family the unaffected father was mosaic, with a fraction of 0.16) and cardioacrofacial dysplasia 2 (OMIM 619143) due to PRKACB [105]; somatic DNAJB1-PRKACA fusion in fibrolamellar hepatocellular carcinoma; striatal degeneration due to PDE8B; neurodevelopmental disorder due to de novo KDM1A missense variants; autosomal recessive spastic paraplegia 59 due to USP8; and the remaining forms of the GNAS spectrum [6, 7, 9, 11, 12]. PDE11A and the genetic background modify the phenotype of CNC and PBMAH [87, 88]. In cardioacrofacial dysplasia 2, four unrelated probands (Denmark, France and Australia) with de novo PRKACB missense variants, one of them mosaic (allele fraction 0.32), had common atrium or atrioventricular septal defect, postaxial polydactyly, short broad hands and feet, dental anomalies and developmental delay in three; two had received a clinical diagnosis of Ellis-van Creveld syndrome [86]. In acrodysostosis type 1, PRKAR1A variants affect cAMP-binding domain B (the most recurrent is the de novo truncating variant NM_002734.5:c.1102C>T p.(Arg368Ter), originally described as “1101C>T”), and the regulatory subunit remains bound to the catalytic subunit without dissociating with cAMP, with resistance to parathyroid hormone (PTH) and thyrotrophin (TSH), severe brachydactyly and cone-shaped epiphyses [31, 82, 84].

3. Clinical Spectrum and Manifestations by System

3.1 Common manifestations of cortisol excess

The clinical picture of hypercortisolism is the same in all entities of the class and varies with intensity, duration and age. The features that best discriminate CS, although insensitive, are easy bruising, facial plethora, proximal myopathy, reddish-purple striae wider than 1 cm and, in children, weight gain with decreasing growth velocity [1]. Less discriminating are depression, fatigue, weight gain, dorsocervical fat pad, full face, central obesity, supraclavicular fullness, thin skin, oedema, acne, hirsutism, poor wound healing and menstrual changes; in children, slow growth, short stature, virilisation, precocious pseudopuberty or delayed puberty [1]. CS is more likely when hypertension, vertebral osteoporosis, type 2 diabetes, hypokalaemia, renal stones or unusual infections appear at a young age [1]. In CD, the prevalence of comorbidities is 50–95% for hypertension, 20–45% for diabetes, 25–100% for obesity, 16–60% for dyslipidaemia, 28–50% for osteoporosis, 15–50% for fractures, 15–18% for venous thromboembolism (VTE) and 20% for infections [26]. Vertebral fractures occur in 30–50% and the risk of VTE is more than 10 times higher than in patients operated on for a non-functioning pituitary adenoma [24]. Recovery after cure is incomplete: metabolic syndrome affects at least two thirds of patients, excess weight and hypertension persist in up to 25%, there are deficits of declarative memory and partially reversible hippocampal atrophy, and bone mineral density recovers over 4–5 years [2].

In children, endogenous CS is rare before 18 years and manifests mainly as failure to gain height with weight gain; above 6 years CD is the most frequent cause and in younger children adrenal causes predominate [24]. In children with CD, severe GH deficiency (<9 mU/L) occurs in 31% and partial deficiency (<30 mU/L) in 54% [24].

The French PNDS brings together the frequency of signs of CS of all causes: obesity or weight gain in 95% (100% in children), facio-truncal fat accumulation and moon face in 90%, reduced libido in 90%, thin fragile skin in 85%, menstrual irregularity in 80%, slowing of growth in 70–80% of children, hypertension and hirsutism in 75%, depression or emotional lability in 70%, bruising in 65%, glucose intolerance and muscle weakness in 60%, osteopenia or fracture and urinary stones in 50% and hypokalaemia in 20–60% [22]. In the series cited by the protocol, hypertension occurs in 58–85% of adults and in 47–49% of children, bone demineralisation in 64–100% (osteopenia in 40–78%, osteoporosis in 22–57%, fractures in 11–76%, more than half asymptomatic vertebral microfractures) and psychiatric disorders in 50–80%, with predominant depression, irritability, early waking and declarative memory deficit, which often precede the physical signs [22]. In children, slowing of growth velocity is constant, half have a height below −2 standard deviations at diagnosis, and the combination of slow growth with weight gain, visible on the body mass index curve, is sufficient to investigate, because hypertension, striae and facio-truncal distribution may be absent [22]. In order of frequency, the paediatric causes are iatrogenic, pituitary (75–90% of endogenous forms, mainly peripubertal), adrenal (~15%, neonatal in MAS or at 2–5 years in ACC) and ectopic (<1%); 70–90% of cases arise in older children and adolescents [22]. In paediatric ACC hyperandrogenism predominates (hirsutism, acne, virilisation), which may attenuate the growth delay, and the cyclical hypercortisolism of PPNAD does not always delay growth before 7–8 years [22].

3.2 PPNAD in Carney complex

PPNAD is the most frequent endocrine tumour of CNC and causes ACTH-independent hypercortisolism with insidious onset: in a minority it manifests in the first 2–3 years of life and in most in the second or third decade [19]. In children, weight gain and growth arrest appear first; in adults, central obesity, moon facies, hirsutism, striae, hypertension, dorsocervical fat pad, muscle weakness, bruising and psychological disturbance [19]. Clinical PPNAD occurs in ~25% of patients with CNC, and the other manifestations have the following frequencies: skin pigmentation >70%, cutaneous or mucosal myxomas >50%, cardiac myxoma 30–50%, breast myxoma 30–50%, somatomammotroph hyperplasia or GH-secreting adenoma up to 75% (clinical acromegaly in ~10% of adults), large-cell calcifying Sertoli cell tumour in >50% of men, thyroid tumours up to 75% and psammomatous melanotic schwannoma in ~10% [19]. Mean life expectancy is ~50 years, with deaths from cardiac myxoma, melanotic schwannoma, thyroid carcinoma and metastatic pancreatic or testicular tumours [19]. In the São Paulo cohort, 83% of probands with PPNAD had overt CS and 17% cyclical CS, 61% had lentigines and 22% cardiac myxomas [83]. Very rarely CNC has a single manifestation, such as isolated PPNAD or acromegaly [19]. In the 11 North American families used to map CNC2, CS was present in 31% of 101 patients [30]. In a Mayo Clinic series, syndromic cardiac myxomas differed from sporadic ones by younger age, familial occurrence, ventricular location (13% versus 0%), multiplicity (50% versus 1%) and recurrence (18% versus 0%) [29]. The 50-year follow-up of a patient seen at 17 years for CS, with mottled brown adrenals, showed a dizygotic twin brother with the same condition and a daughter with PPNAD and nasopharyngeal schwannoma [29].

3.3 Isolated PPNAD and PDE11A-associated micronodular disease

The phenotype associated with PDE11A is bilateral micronodular adrenal Cushing in childhood or young adulthood, with growth failure, osteopenia or fragility fracture, amenorrhoea and variable cushingoid features, and with a paradoxical rise in cortisol after high-dose dexamethasone [8]. Histology generally shows little pigmentation and there are no other tumours [19]. In the original description of PPNAD2, most glands were of normal size and weight, with multiple small yellow to dark brown nodules on a cortex of uniform appearance; microscopy showed moderate diffuse cortical hyperplasia with mostly non-pigmented nodules, multiple capsular defects and extra-adrenal cortical excrescences with micronodules, and electron microscopy showed lipofuscin granules [36]. Hypercortisolism may be mild and the glands may appear normal on computed tomography (CT), as in the case in section 10 [38].

3.4 PRKACA copy gain

Patients with PRKACA copy gain present with ACTH-independent Cushing, with micronodular hyperplasia in early childhood (Lodish’s three sporadic cases underwent bilateral adrenalectomy at that age) and macronodular hyperplasia in adulthood (mother–son pair) [41]. Triplication was associated with a more severe phenotype [41].

3.5 Cortisol-producing adenoma with somatic PRKACA

Adenomas with p.Leu206Arg are associated with overt CS and are absent in patients with subclinical hypercortisolism [40]. They are smaller and produce more cortisol than adenomas without the variant [39]. There are no extra-adrenal manifestations and no familial risk.

3.6 ARMC5-associated PBMAH

PBMAH typically presents between 45 and 65 years, with ~60% women, often as an incidental finding on CT [5]. Fewer than 25% of patients diagnosed today have the classical signs of CS; diabetes occurs in 30–40%, hypertension in 65–85%, osteoporosis in at least 20% and hypokalaemia in ~10% (which requires investigation of aldosterone co-secretion), and there may be hyperandrogenism [5]. PBMAH accounts for 15–20% of bilateral incidentalomas and up to one third of benign bilateral cortical lesions [5]. The pre-diagnostic course is long and insidious [10]. In the series predating molecular genetics, presentation occurred in the fifth or sixth decade, about 10 years later than in other causes of CS; in 9 patients undergoing curative bilateral adrenalectomy (mean age 56 years), 8 had hypertension, there were subtle signs of CS up to 20 years earlier, the glands weighed 16.7–218 g combined with nodules of 1–4.2 cm, and no patient developed Nelson syndrome or malignancy; in an imaging series of 11 patients, the glands reached 300 g combined and the nodules 5 cm, with mild clinical manifestations in many [45]. In families (up to 45 families with 170 affected individuals described), index cases were diagnosed between 38 and 69 years and relatives had abnormalities from 17 years [5]. ARMC5 carriers have more severe disease: in 352 patients, UFC was 2.32 versus 1.11 times the upper limit of normal (ULN), maximum adrenal diameter 104 versus 83 mm and the proportion treated 67.9% versus 36.8% [90]. Histology corresponds to PBMAH subtype 1 (coalescent yellow nodules with 70–90% clear cells and fibrous septa) [20]. Meningioma is the only extra-adrenal tumour association described [20].

3.7 KDM1A-associated GIP-dependent PBMAH

Food-dependent Cushing has a distinctive profile: low fasting morning cortisol, which rises after meals, and high midnight cortisol, with an inverted rhythm [48]. In the series of 301 index cases, UFC was 3.0 times the ULN in KDM1A carriers versus 1.36 in ARMC5 carriers and 0.66 in patients without a variant; fasting morning cortisol was 192, 407 and 428 nmol/L and midnight cortisol 487, 297 and 172 nmol/L, respectively [48]. All KDM1A carriers were women, versus 65% of ARMC5 carriers and 67% of patients without a variant [48]. Multiple myeloma and monoclonal gammopathy have been described in relatives of KDM1A carriers [5].

3.8 MEN1 and MEN4

In MEN1, pituitary adenomas occur in 30–40% of patients (15–55% depending on the series), are the first manifestation in 25% of sporadic and 10% of familial cases, and are distributed as prolactinomas 60%, GH-secreting 25%, GH/prolactin 10%, ACTH-secreting <5% and non-functioning <10% [13]. The overall penetrance of MEN1 is ~94% by 50 years; in a series of 63 families, it was 7%, 52%, 87% and 98% at 10, 20, 30 and 40 years, and more than 10% of variants were de novo [50]. Adrenocortical lesions are the first neoplasm in 6% of patients, concurrent in 33% and subsequent in 61% [5]. Thymic carcinoids rarely secrete ACTH but may cause ectopic CS [13]. In MEN4, the pituitary tumour is the initial manifestation in ~23%, more often a microadenoma, with a median age at diagnosis of 39 years (5–79); in a series of 65 patients, pituitary tumours occurred in 30–45% (33% ACTH-secreting) and adrenocortical tumours in ~4–7% [14, 106].

3.9 USP8-associated Cushing disease and rare pituitary forms

Corticotroph tumours with somatic USP8 are small, with high ACTH secretion, more frequent in young women and in adults than in children, and are inversely associated with post-operative adrenal insufficiency [56, 85]. The germline form combines recurrent CD with developmental delay, dysmorphism, ichthyosiform hyperkeratosis, chronic lung and kidney disease, dilated cardiomyopathy, hyperinsulinism and GH deficiency [97]. Pituitary blastoma occurs mainly up to 2 years of age, with Cushing, ophthalmoplegia or diabetes insipidus [15]. In Lynch syndrome, pituitary tumours are rare but may be aggressive [99].

3.10 Neonatal Cushing in McCune-Albright syndrome

In the NIH cohort, CS occurred in 7.1% of 112 patients with MAS; adding 21 published cases, the median age at diagnosis was 3 months, with cushingoid facies in 66.7%, growth delay in 60.0%, low birth weight in 50.0%, liver disease in 36.7% and cardiac disease in 26.7% [23]. Six patients (20.0%) died, four after adrenalectomy, and death was more likely with cardiac disease (odds ratio 13.3); of the 23 survivors, 13 underwent adrenalectomy and 10 had spontaneous resolution, and two of these retained low-level autonomous function with biochemical adrenal insufficiency 3 and 15 years later [23]. Cognitive or developmental impairment occurred in 44.4% of patients with CS versus 4.8% of the others [23]. Clinically, the infant presents with hypertension, facial plethora, abdominal obesity, developmental delay, poor weight gain, reduced linear growth and low weight for gestational age [18]. Hypercortisolism is unlikely after the first year and the risk is considered nil after 3 years [18]. In children, MAS may also present as bilateral macronodular hyperplasia, with an aggressive and fatal course or with spontaneous remission [2]. Kirk and colleagues described five children (four girls) with CS before 6 months: two had spontaneous resolution and three required bilateral adrenalectomy, one of them at 3 months for nodular hyperplasia; all the girls had precocious puberty and three children had nephrocalcinosis, attributed by the authors to cortisol-induced hypercalciuria [58]. CS present at birth, with hyperthyroidism and skin pigmentation, has also been described [58].

3.11 Adrenocortical carcinoma in predisposition syndromes

Paediatric ACC manifests as virilisation, Cushing or both, and examination of the child with Li-Fraumeni syndrome includes looking for a cushingoid appearance and virilisation [16]. In the Paraná newborn screening, p.(Arg337His) carriers had smaller adrenocortical tumours when under surveillance [59] (section 9). In adults, ACC has an incidence of 0.7–2.0 per million per year, a peak at 40–60 years and 55–60% women [25].

3.12 Cyclical forms and course without treatment

Cyclical CS, with at least two peaks and one trough of cortisol production, was described in 17% of probands with PPNAD in the São Paulo cohort [83]. In an international cohort of 110 patients with cyclical CS of all causes (76% women, median 44 years), the origin was pituitary in 64%, ectopic in 23%, adrenal in 3% and occult in 11%; UFC peaks had a median of 7.40 times the ULN and troughs 0.31, cycles were irregular in 86%, there was spontaneous adrenal insufficiency in 28%, and imaging missed the tumour in 32% [107]. Without effective treatment, median survival in CS was 4.6 years in 1952 [2]. Natural history data on CNC, PBMAH and MAS come from reference-centre series with largely treated patients; the proportion of spontaneous remission in MAS and the course of asymptomatic ARMC5 or PRKAR1A carriers with MACS have not been established in prospective cohorts [5, 23, 83].

4. Clinical Recognition and Warning Signs

4.1 When to test for hypercortisolism

The Endocrine Society recommends testing for CS in patients with features unusual for age (osteoporosis or hypertension in young people), in patients with multiple and progressive features, particularly the most discriminating ones, in children with a falling height percentile and rising weight, and in patients with an adrenal incidentaloma consistent with an adenoma; it advises against widespread screening of other groups [1]. The 2023 European guidelines recommend the 1 mg DST in all adrenal incidentalomas, except in frail patients with limited life expectancy [79]. The French PNDS recommends testing for CS in the presence of facio-truncal fat distribution or at least one sign of hypercatabolism (skin fragility, bruising, striae, proximal amyotrophy, osteoporosis), of a manifestation that is rare for age (hypertension before 40 years, osteoporosis in men before 50 years), of an unusual course under conventional treatment and of any adrenal tumour, pituitary adenoma or tumour capable of ectopic ACTH secretion, especially with hypokalaemia [22]. CS is rare in the common diseases it mimics, affecting <1% of unselected patients with type 2 diabetes and 0.5–1.5% of hypertensive patients, so that in these groups biochemical testing requires pointers; in adrenal incidentalomas, cortisol secretion is present in 1–29% and overt CS in 1–3% [22]. In osteoporosis, the decision to test weighs severity, vertebral fractures, male sex, age <50 years and signs of hypercatabolism; in women with oligomenorrhoea or amenorrhoea associated with obesity or hirsutism, signs of CS are sought [22]. Suspected CS in a pregnant woman or a child is referred immediately to a reference or competence centre [22].

4.2 When to suspect a genetic cause

Suspicion of a genetic cause rests on age, imaging pattern, biochemistry and associated manifestations. The following table summarises the contexts that guide testing.

4.3 Emergency signs

Severe hypercortisolism requires treatment within 24–72 hours when there are life-threatening complications: severe infection, pulmonary embolism or other VTE, cardiovascular complications or acute psychosis [2]. Warning signs include profound hypokalaemia, uncontrolled hyperglycaemia, severe hypertension, disabling myopathy and UFC >5 times the ULN [2, 26]. In infants with MAS, the combination of Cushing with cardiac or liver disease defines a group with high mortality [23]. After bilateral adrenalectomy, or during treatment with steroidogenesis inhibitors, acute adrenal insufficiency is the main emergency, with adrenal crises at 9.3 per 100 patient-years after bilateral adrenalectomy [2]. The patient with known PPNAD and cardiac myxoma is at risk of embolism, and detection of CNC in a patient with PPNAD requires a search for atrial myxoma [2]. The PNDS defines severe CS as intense clinical and biochemical hypercortisolism, generally with hypokalaemia and short-term life-threatening complications, sometimes in a purely catabolic form without fat accumulation, caused mainly by ectopic ACTH secretion and more rarely by CD or ACC, which requires admission and rapid treatment [22].

4.4 Newborn screening

There is no newborn screening for hypercortisolism. In the state of Paraná (Brazil), free newborn screening for the TP53 variant p.(Arg337His) was offered to 180,000 newborns: 171,649 were screened and 461 were carriers (0.27%); up to April 2012, adrenocortical tumours arose in 11 carriers and in 2 screened non-carriers, 347 of 699 carriers (49.6%) accepted surveillance, tumours detected under surveillance were smaller and non-participants had more advanced tumours (4 at stage III, 2 deaths) [59]. GeneReviews recommends targeted testing for the p.(Arg337His) variant first in any paediatric cancer in an individual with ancestry from South or Southeast Brazil [16].

5. Diagnosis: Criteria, Tests and Algorithms

5.1 First step: confirming endogenous hypercortisolism

Before any test, exogenous glucocorticoids must be excluded by a drug history, including topical, inhaled and intra-articular routes [1]. The initial test is one of the following, chosen according to the patient: UFC (at least two collections), late-night salivary cortisol (two measurements), overnight 1 mg DST, or 2 mg/day DST for 48 hours [1]. The 2021 Pituitary Society consensus recommends starting with the DST, UFC or late-night salivary cortisol according to availability and, when an adrenal tumour is suspected, starting with the DST [24]. The criteria and performance are given in the table.

ELISA: enzyme-linked immunosorbent assay; LC-MS/MS: liquid chromatography with tandem mass spectrometry; CRH: corticotrophin-releasing hormone.

The guidelines do not recommend random serum cortisol or ACTH, urinary 17-ketosteroids, the insulin tolerance test, loperamide, pituitary or adrenal imaging or the 8 mg DST for the diagnosis of hypercortisolism [1]. Two concordant positive tests, once pseudo-Cushing states have been excluded, lead to tests for the cause; two concordant negative tests close the investigation, unless a cyclical form is suspected; discordant results require follow-up [1]. Pseudo-Cushing states include pregnancy, depression and other psychiatric disorders, alcohol dependence, glucocorticoid resistance, morbid obesity and poorly controlled diabetes; UFC is almost always <3 times normal, and the dexamethasone-CRH test, the 48 h DST or desmopressin may discriminate, with surveillance for 3–6 months [1, 24]. Ovine CRH is not available in the USA, Canada, Brazil, Argentina and Mexico [24].

Several situations change the choice of test. In pregnancy UFC is used and not dexamethasone, and in the second and third trimesters UFC indicates CS only above 3 times the ULN; with enzyme-inducing antiepileptic drugs dexamethasone is not used; in severe renal failure the DST is preferred to UFC; when a cyclical form is suspected, repeated UFC or late-night salivary cortisol are used; in incidentaloma, the DST or late-night cortisol rather than UFC [1]. The DST is falsely positive in 50% of women on oral contraception, which should be stopped 6 weeks beforehand [1]. Interfering drugs include CYP3A4 inducers that accelerate dexamethasone clearance (phenobarbital, phenytoin, carbamazepine, primidone, rifampicin, rifapentine, ethosuximide, pioglitazone, St John’s wort), inhibitors that slow it (aprepitant, itraconazole, ritonavir, fluoxetine, diltiazem, cimetidine), oestrogens and mitotane (which increase corticosteroid-binding globulin) and liquorice and carbenoxolone (which increase UFC) [1, 24].

The French PNDS spells out the first step. The 24-h UFC is accompanied by urinary creatinine, which shows whether the collection is complete; it loses value with diuresis >5 L or creatinine clearance <60 mL/min, has an intra-individual variability of ~50% in CD (several collections) and is practically diagnostic above 3–4 times the ULN; mass spectrometry gives lower values than immunoassays, with minimal diagnostic gain if the immunoassay is specific and has its own reference values [22]. Late-night salivary cortisol is measured on two non-consecutive days, is little altered by combined oestrogen–progestogen contraception, rises with gingival bleeding and, at the time of the protocol, was not reimbursed in France; midnight serum cortisol <50 nmol/L excludes CS, but requires admission [22]. For the 1 mg DST, the PNDS adopts the threshold of 50 nmol/L (18 µg/L), rather than 138 nmol/L, because of sensitivity and the cardiovascular morbidity and mortality data from incidentalomas, and suggests measuring dexamethasone simultaneously to identify false positives due to variable absorption or hepatic metabolism [22]. The proposed sequence is: with a normal first test, a second is done only if clinical suspicion is strong; with an abnormal first test, a second first-line test is done immediately; with two abnormal tests, a systematic second-line test is not needed; with discordant results or results close to the thresholds, a 24-h cortisol profile or the 2 mg/day DST for 48 h is performed in a specialist setting [22]. In renal failure, UFC is not useful and the other tests may be falsely abnormal, so testing starts with the 1 mg DST and late-night cortisol, both useful when normal; shift workers who invert their rhythm are tested after 7 days without night work [22]. In fluctuating CS, suspicion arises from discordance between clinical and biochemical findings, flares are generally accompanied by frank hypercortisolism and repeated salivary cortisol at home during a flare is the most practical test; a fluctuating picture may also result from covert glucocorticoid intake [22]. In pseudo-Cushing (depression, chronic alcoholism, anorexia nervosa), UFC does not exceed 4 times the ULN and the circadian rhythm is preserved; when in doubt, repeated late-night cortisol, desmopressin, the 48 h DST or the DST combined with CRH are used, with no ranking of performance, and IPSS should not be performed [22].

In children, the PNDS considers 24-h UFC, ideally on 3 consecutive days and referred to urinary creatinine or body surface area, the test of choice in older children; evening serum cortisol >4.4 µg/dL (122 nmol/L) is very sensitive but less practical; when UFC is not clearly raised, the first choice is the DST with 15 µg/kg dexamethasone (maximum 1 mg) at midnight, with 8 h cortisol >50 nmol/L favouring CS, a threshold extrapolated from adults for lack of paediatric sensitivity and specificity data [22].

5.2 Second step: ACTH dependence and localisation

With confirmed hypercortisolism, plasma ACTH separates ACTH-dependent from ACTH-independent forms. In dependent forms, pituitary MRI is the method of choice; 1.5 T MRI detects ~50% of microadenomas and about one third of MRIs are negative, so 3 T is suggested [24]. No single test distinguishes CD from ectopic secretion with certainty. Inferior petrosal sinus sampling (IPSS) is the reference standard, with a central/peripheral gradient <2 at baseline or <3 after stimulation suggesting ectopic secretion, measurement of prolactin and the patient in a hypercortisolaemic phase; it is dispensable with a tumour ≥10 mm and concordant dynamic tests, recommended with a tumour <6 mm and preferred by most with a tumour of 6–9 mm, and is not useful for lateralisation [24]. 68Ga-DOTATATE localises ~65% of ectopic tumours [24]. In children, IPSS has a more limited role and the dexamethasone-CRH test is not useful [24]. In cyclical CS, the active phase must be documented before dynamic tests and IPSS; in the international cohort, 18% of IPSS were performed in a trough and 8% of patients were operated on at the wrong site [24, 107].

The PNDS specifies the ACTH thresholds: sampling at 8–9 h, repeated at least twice with simultaneous cortisol, in a specialist laboratory because of the fragility of the molecule; <10 ng/L (2.2 pmol/L) on two occasions confirms adrenal origin, and 10–20 ng/L is a grey zone (mild CD with fluctuating secretion, mild adrenal hypercortisolism with incomplete suppression, paracrine ACTH secretion in the adrenal) in which an ACTH response to CRH >50% of baseline or with a peak >30 ng/L excludes adrenal origin and adrenal CT is legitimate [22]. In children, ACTH <5 ng/L favours adrenal origin and values of 5–29 ng/L lead to dual imaging (adrenal CT and pituitary MRI) [22]. In the ACTH-dependent pathway, the probability of CD exceeds 90% in a middle-aged woman with moderate CS, without hypokalaemia or very high ACTH and developing over more than a year, whereas advanced age, male sex, rapid progression, intense catabolism, hypokalaemia, UFC well above 5 times the ULN, cortisol >1000 nmol/L and ACTH >150 ng/L suggest ectopic secretion; the protocol requires at least two dynamic tests in a non-invasive strategy, considers IPSS (gradient ≥2 at baseline or ≥3 after CRH, or with desmopressin) the best-performing test, with serious complications well below 1% in experienced hands, and notes that corticotroph tumours have a median size of 5 mm [22]. In the peripubertal child, ACTH-dependent CS is CD in the overwhelming majority of cases even with a normal MRI, and IPSS is reserved for particular situations in an expert centre [22]. The conversions used are cortisol 50 nmol/L = 18 µg/L and ACTH 2.2 pmol/L = 10 ng/L [22].

5.3 Adrenal imaging, bilateral lesions and MACS

CT is the initial examination in ACTH-independent forms. In PPNAD the glands are frequently normal or slightly enlarged, with millimetric nodules that CT may not show [8, 38]. The 2023 European guidelines recommend assessing each lesion of a bilateral incidentaloma individually, with the same hormonal work-up as for a unilateral lesion, and suggest four categories: bilateral (macronodular) hyperplasia, bilateral adenomas, two similar non-adenomatous masses and two different masses [79]. In bilateral hyperplasia without autonomous secretion they suggest measuring 17-hydroxyprogesterone to exclude congenital adrenal hyperplasia due to 21-hydroxylase deficiency; once this is excluded, PBMAH is considered, in which 17-hydroxyprogesterone may also be raised but ACTH is suppressed [79]. Post-DST cortisol ≤50 nmol/L excludes autonomous secretion and >50 nmol/L without signs of overt CS defines MACS, without the 2016 subcategories; MACS does not carry a high risk of progression to overt CS, but requires screening for hypertension, type 2 diabetes and vertebral fractures [79]. In PBMAH with MACS, the number of nodules correlates with the probability of an ARMC5 variant [79]. Norcholesterol scintigraphy may show asymmetric uptake that guides unilateral adrenalectomy [108, 109]. Fluorodeoxyglucose uptake on positron emission tomography does not indicate malignancy in this class: bilateral uptake has been described in a 32-year-old woman with PPNAD [29].

The PNDS adds imaging criteria. On CT, a lesion ≤30 mm, homogeneous and with unenhanced density ≤20 HU, or ≤40 mm with ≤15 HU, would have a positive predictive value for benignity of 100%, and a bulky, heterogeneous, lipid-poor mass or one with growth ≥20% of the largest diameter in 6 months raises suspicion of ACC; chemical-shift MRI is not validated in secreting tumours; on FDG PET, a tumour/liver uptake ratio >1.5 suggests malignancy and above 2 the main differential is oncocytoma (ratio often >4) [22]. The PNDS density criterion is more permissive than that of the 2023 European guideline, which remains the reference: only a homogeneous mass with ≤10 HU requires no further imaging; with 11–20 HU, <4 cm and without significant hormone excess, immediate additional imaging or unenhanced CT at 12 months is suggested, and a heterogeneous mass ≥4 cm or one with >20 HU is discussed at a multidisciplinary meeting [79]. When PPNAD is suspected, morphological imaging may show apparently normal adrenals, unilateral or bilateral changes and coexisting macronodules, and functional cortical imaging, with any tracer, generally shows bilateral, possibly asymmetric, increased uptake; in PBMAH, 131I-norcholesterol scintigraphy may be discussed before a unilateral adrenalectomy, especially with masses of similar volume, the disease may be hypermetabolic on FDG and, in cases selected at a multidisciplinary meeting, adrenal vein sampling with cortisol, adrenaline and aldosterone helps to lateralise secretion [22]. The protocol requires adrenal imaging to be performed or reviewed in a reference or competence centre before deciding on the strategy [22].

5.4 Entity-specific tests

The modified Liddle test (low-dose followed by high-dose dexamethasone, with urinary cortisol) is the most specific single biochemical confirmation of PPNAD: the paradoxical rise in urinary glucocorticoids with dexamethasone is a major criterion of CNC [6, 19]. In a series of 13 patients with PPNAD, 9 (70%) had a paradoxical rise in urinary free cortisol on the sixth day of the test, a response that separated them from patients with macronodular hyperplasia [33]. Ophthalmological examination contributes to the clinical diagnosis: in 63 patients with CNC, there were facial and eyelid lentigines in 70%, pigmented lesions of the caruncle or conjunctival semilunar fold in 27% and eyelid myxomas in 16% [29]. The clinical diagnostic criteria for CNC require two major criteria, or one major criterion with a PRKAR1A variant [19, 110]. The PNDS describes a paradoxical rise >50% in UFC after 8 mg dexamethasone as specific but present in only 38% of patients operated on for PPNAD, which limits the value of a negative test; in children, the regimen uses 8 doses of dexamethasone 6-hourly at 7.5 µg/kg per dose (maximum 0.5 mg per dose) [22].

In PBMAH, the DST alone may fail to detect the food-dependent form, because overnight fasting cortisol is low [5]. A ratio of fasting morning plasma cortisol to midnight cortisol <0.65 detected food-dependent Cushing with a sensitivity and specificity of 100% in 301 index cases and indicates KDM1A testing; the ratio identifies the physiology, not the gene [48]. Bertherat and colleagues recommend screening for ectopic GIPR in all PBMAH with cortisol before and 2 hours after 75 g oral glucose or a mixed meal, considering a reproducible rise >50% positive; confirmation includes no response to intravenous glucose, inhibition by octreotide and GIP infusion [5]. The in vivo aberrant receptor protocol tests posture, meal, vasopressin, metoclopramide or cisapride, gonadotrophin-releasing hormone, thyrotrophin-releasing hormone, glucagon and GH-releasing hormone [5]; in 2015 the Endocrine Society considered detailed assessment “a research undertaking” [2]. The PNDS reserves these tests for specialist centres [22].

In MAS, adrenal assessment is recommended at the initial presentation of all patients, regardless of symptoms, with investigation of hypercortisolism in infants with clinical signs; routine biochemical surveillance is not indicated [18]. In MEN4 with suspected CD, UFC, late-night salivary cortisol or the 1 mg DST are used, with dynamic tests if screening is abnormal [14].

5.5 Diagnostic algorithm

5.6 Genetic testing by phenotype

A targeted next-generation sequencing (NGS) panel is the recommended approach for PBMAH, with interpretation of missense variants by ACMG/AMP criteria, genetic counselling and written consent [5]. The choice of genes follows the phenotype.

PNA: peptide nucleic acid (mutant allele enrichment technique). In somatic forms (USP8, PRKACA NM_002730.4:c.617T>G p.(Leu206Arg)), tumour sequencing is of research or prognostic interest and cannot be used to assess familial risk [7, 12]. The 2018 European ACC guidelines make no recommendation for or against somatic testing [25].

The French PNDS recommends systematically looking for a genetic predisposition in bilateral adrenal forms, with an NGS panel capable of detecting point variants and large rearrangements (described in ARMC5, PRKACA, PRKAR1A, MEN1 and APC); if the panel is negative, the case is presented at the national multidisciplinary meeting of the reference centre for exome or genome sequencing under the Plan France Médecine Génomique 2025, and in CD the same strategy applies, with an initial targeted exome [22]. According to the protocol, in 2020 predisposition to cortisol-producing adenoma had been described only in MEN1 and familial adenomatous polyposis, and adult ACC reveals a constitutional predisposition syndrome (Li-Fraumeni, Lynch) in 1–5%, which justifies a careful personal and family history and discussion of genetic testing even without clinical pointers [22].

5.7 Limitations of the tests

A negative result does not exclude a genetic cause. PRKAR1A sequencing does not detect large deletions, which require copy-number analysis, and PRKACA copy gain is visible only on chromosomal microarray [7, 81]. In PBMAH, the somatic second hit does not appear in constitutional testing, and more than 75% of index cases remain without an identified molecular cause [10, 20]. In MAS, mosaicism means that the GNAS variant may be absent from blood; affected tissue has greater sensitivity, particularly endocrine organs, and skin lower sensitivity [18]. In a study of 113 patients with at least one sign of MAS, the codon 201 variant was detected in 43% overall and in more than 90% when affected tissue was available, except for skin (3 of 11 samples positive); in blood, detection was 46% in patients with the classical triad, 21% with two signs and 8% with one sign [58]. Filtering algorithms may eliminate relevant variants: in the Carling case, the first report was negative because the truncating PDE11A variant was classified as likely benign and omitted, and it was identified only after reanalysis targeted at the familial variant [38]. Neither biochemistry nor histology identifies the PPNAD gene [8]. The frequent PDE11A missense variants (p.(Arg804His), p.(Arg867Gly)) are present in controls and should not be reported as a Mendelian cause [8, 87]. In ARMC5, several missense variants published as pathogenic have a population frequency incompatible with that classification [20].

5.8 Report content, VUS and segregation

The report should state the gene, the reference transcript with version (for example, NM_002734.5 for PRKAR1A and NM_001105247.2 for ARMC5), the nucleotide and protein HGVS notation, zygosity, sample type (blood or tissue, with allele fraction when mosaicism is suspected), the method (sequencing, copy-number analysis, microarray) and the ACMG/AMP class [5, 82]. A variant of uncertain significance (VUS) in PRKAR1A neither establishes nor excludes the diagnosis of CNC [19]. In PBMAH, demonstration of the somatic second hit in the nodule, family segregation and population frequency are the elements that allow missense variants to be reclassified [20]. The PBMAH case with the ARMC5 VUS c.2525T>C p.(Phe842Ser) illustrates that a VUS cannot be used to assert causality or to guide predictive testing; the authors planned a segregation study [108].

5.9 Prenatal and preimplantation diagnosis

When the familial PRKAR1A variant is known, prenatal diagnosis and preimplantation genetic testing are possible [19]. In MEN1, prenatal diagnosis by chorionic villus sampling is possible when the familial variant is known [96]. On fetal ultrasound, a cardiac tumour may suggest CNC [19]. For ARMC5, KDM1A and TP53, the sources consulted do not describe specific experience of prenatal diagnosis; the technical application is the same as for any known AD variant, and the decision depends on incomplete penetrance and late onset, which weigh in counselling (section 8). In MAS, the variant is post-zygotic and the recurrence risk is very low, so there is no indication for prenatal diagnosis [18, 111]. In France, prenatal or preimplantation diagnosis in complex syndromic entities that include CS is decided after discussion of the case at a multidisciplinary prenatal diagnosis centre (CPDPN) [22].

5.10 Initial assessment of severity and comorbidities

The French PNDS requires all complications to be sought, at least clinically, and the therapeutic choice to weigh age, history, wish for pregnancy and capacity for adherence [22]. The table summarises the proposed work-up.

PT and aPTT: prothrombin time and activated partial thromboplastin time; BNP: B-type natriuretic peptide; ABPM: 24-h ambulatory BP monitoring; CMV: cytomegalovirus; IGRA: interferon-gamma release assay; DOC: 11-deoxycorticosterone; DHEA: dehydroepiandrosterone.

The information given at disclosure, with written support, covers the pathophysiology, complications, warning signs, therapeutic options and their limits, follow-up and the importance of adherence; for women of childbearing age, it includes the need for reliable contraception during hypercortisolism and under certain treatments and the temporary contraindications to pregnancy and breastfeeding; for children, it is given to both parents and to the child, adapted to age, with the paediatric oncologist if there is a malignant tumour [22].

6. Differential Diagnosis

6.1 Comparative table

AR: autosomal recessive; X-LAG: X-linked acrogigantism; PitNET: pituitary neuroendocrine tumour.

6.2 Main distinctions

The first distinction is between pathological hypercortisolism and pseudo-Cushing states, which share moderate biochemical abnormalities without a tumour; repeat testing and surveillance of the course are more useful than a single test [1, 24]. The second is ACTH dependence: suppressed ACTH points to adrenal disease (PPNAD, PBMAH, adenoma, ACC, MAS), whereas non-suppressed ACTH points to CD or ectopic secretion [24]. Within bilateral adrenal disease, PPNAD has nodules <1 cm, glands sometimes normal on CT, onset in childhood or young adulthood and a paradoxical response to dexamethasone; PBMAH has macronodules >1 cm and markedly enlarged glands in middle-aged adults; secondary hyperplasia and congenital adrenal hyperplasia keep ACTH raised [5, 32, 44, 79].

In the child with Cushing, age guides the diagnosis: in infants under one year, MAS and pituitary blastoma; up to 6 years, adrenal causes (including ACC in Li-Fraumeni syndrome and BWS and PRKACA copy gain); above 6 years, CD [23, 24, 41, 77]. Paediatric ACC may manifest as virilisation, Cushing or both, and examination of the child looks for both signs [16].

Carney triad (unrelated to PRKAR1A) and Carney-Stratakis syndrome (gastrointestinal stromal tumour and paraganglioma) share the eponym but do not cause PPNAD [19, 78]. The MYH8 variant with trismus and pseudocamptodactyly also shares the name without any relationship to hypercortisolism [112]. NF1 and its segmental mosaic form have only a chance association with CS, either through ectopic ACTH from a malignant nerve sheath tumour or through macronodular hyperplasia with a second hit in NF1 [61, 62].

7. Treatments and Risk Management Strategies

7.1 Principles and objectives

In overt CS, the objective is to normalise cortisol or its action at the receptor and to treat comorbidities; treatment to lower cortisol is not given without an established diagnosis, and it is suggested not to treat borderline biochemical abnormalities without specific signs [2]. The Endocrine Society recommends education of the patient and family, treatment of cortisol-dependent comorbidities (psychiatric disorders, diabetes, hypertension, hypokalaemia, infections, dyslipidaemia, osteoporosis, physical condition), follow-up by a multidisciplinary team with an experienced endocrinologist, assessment of thrombotic risk, perioperative VTE prophylaxis and age-appropriate vaccination (influenza, herpes zoster, pneumococcal) [2]. First-line treatment is resection of the primary lesion in CD, in ectopic secretion and in adrenal disease, including bilateral disease, unless surgery is not possible or does not significantly reduce glucocorticoid excess [2]. The Pituitary Society consensus recommends treatment in pituitary tumour centres of excellence [24]. The French PNDS sets as objectives excision of the causal lesion, correction of hypercortisolism, recovery of normal corticotroph function and treatment of complications, with a multidisciplinary decision in a reference or competence centre; off-label prescription (outside the marketing authorisation) is the prescriber’s responsibility, who informs the patient, and is decided case by case at a multidisciplinary consultation meeting [22].

7.2 Surgery by entity

PPNAD and CNC. Laparoscopic bilateral adrenalectomy is the definitive treatment of choice and curative in most cases, at any age [2, 19]. In some paediatric patients unilateral adrenalectomy produces clinical and biochemical improvement, but there is recurrence requiring removal of the second gland [2]. The systematic review of 210 PPNAD cases discusses unilateral adrenalectomy as an option to preserve a safer perinatal course in women wishing to conceive [34]. In the carrier without hypercortisolism there is no treatment; in the Carling family, surgery was performed only after mild hypercortisolism with an impact on growth and puberty had been demonstrated [38]. The Endocrine Society recommends periodic screening of patients with PPNAD for manifestations of CNC, particularly atrial myxoma, and testing relatives when CNC is confirmed [2]. The French PNDS indicates endoscopic bilateral adrenalectomy in the absence of technical limitations, anticortisol drugs in particular situations and unilateral adrenalectomy only in very particular cases, after morphological assessment including 131I-norcholesterol scintigraphy [22].

PRKACA copy gain. Four of five patients underwent bilateral adrenalectomy, with a good long-term outcome; the patient with unilateral adrenalectomy maintained raised UFC [42].

PBMAH. Treatment is reserved for overt CS or the symptomatic mild form; non-secreting nodules are not treated [5, 115]. With normal UFC, normal ACTH, post-DST cortisol <138 nmol/L (<5 µg/dL) and no comorbidities, surveillance without surgery is reasonable [5]. The 2015 Endocrine Society guideline recommended surgical resection of bilateral adrenal disease and laparoscopic bilateral adrenalectomy as the surgical treatment of choice, allowing removal of the larger gland in older patients [2]. Subsequent data favour unilateral adrenalectomy of the larger gland: in 31 publications with 286 patients, initial remission was 77%, recurrence 29% and contralateral completion 31%, with a median time to the second surgery of 22 months in overt CS and 72 months in the mild form; transient adrenal insufficiency is frequent (50% in one series) [5]. According to the 2026 review, unilateral adrenalectomy normalises cortisol in 60% and causes adrenal insufficiency in 20%, but recurrence occurs in 55% of patients with overt CS due to bilateral hyperplasia, whereas complete bilateral adrenalectomy has no recurrence [26]. The 2023 European guidelines suggest not performing bilateral adrenalectomy without signs of overt CS and individualising bilateral MACS (age, sex, degree of autonomy, comorbidities, preference) [79]. In PBMAH with aldosterone co-secretion, adrenal vein sampling corrected for metanephrines may guide surgery [5]. The PNDS chooses between unilateral and bilateral surgery on the basis of clinical, hormonal and imaging data, and allows anticortisol therapy or blockade of aberrant receptors in an expert centre [22].

Unilateral adenoma. Unilateral adrenalectomy by an experienced surgeon is recommended in all benign unilateral disease and cures 100% of adenomas with complete resection [2, 26]. Adrenal insufficiency may last months to years after surgery [79]. The PNDS allows medical preparation with an anticortisol drug before surgery, by the laparoscopic route, and indicates intra- and post-operative hydrocortisone, transient for months or years or lifelong [22].

Cushing disease. Selective transsphenoidal adenomectomy (TSS) by an experienced pituitary neurosurgeon is the treatment of choice in children and adults [2]. Remission (post-operative cortisol <55 nmol/L, <2 µg/dL) occurs in ~80% of microadenomas and ~60% of macroadenomas; new hypopituitarism occurs in ~10% and permanent diabetes insipidus, cerebrospinal fluid leak and VTE in <5%, with mortality <1% [24]. Recurrence occurs in 5–35%, half in the first 5 years and half up to 10 years or more; reoperation, when there is a visible tumour, gives remission in 37–88% [24]. The Endocrine Society recommends measuring sodium several times on days 5–14 after TSS (hyponatraemia in 5–10%), free thyroxine and prolactin at 1–2 weeks, and MRI 1–3 months after successful surgery [2]. In MEN1, excision of the corticotroph tumour cured 92% of microadenomas and 67% of macroadenomas in the Beckers series [13]; in MEN4, surgery by a surgeon with pituitary experience is recommended [14]. Pituitary blastoma follows the approach of DICER1 tumour predisposition syndrome. The French PNDS gives remission of 80–90% in an accessible non-invasive microadenoma, allows TSS with a negative MRI if dynamic tests or IPSS confirm pituitary origin, states that some teams delay post-operative hydrocortisone in order to follow cortisol and reoperate immediately if there is no cure, notes that post-operative diabetes insipidus is more frequent than with other adenomas and, in case of failure, discusses reoperation, medical therapy, bilateral adrenalectomy or radiotherapy; an invasive macroadenoma may require decompressive surgery, radiotherapy and antisecretory therapy, and a wish for pregnancy in the short term contraindicates medical therapy, except cabergoline, which often leads to discussion of bilateral adrenalectomy [22]. In children, TSS is first line, with cure in 45–85%, comparable to adults in expert teams but with more recurrences, earlier recurrence and more post-operative anterior pituitary insufficiency; radiotherapy for recurrence causes GH deficiency in 90% and, more rarely, thyrotroph or gonadotroph deficiency, and there are no long-term data on cognitive development or on paediatric stereotactic radiosurgery [22].

Radiotherapy. Conventional radiotherapy (45–50 Gy in fractions <2 Gy) or radiosurgery (~20 Gy) gives remission in about two thirds of patients over years, with tumour control of ~95% and hypopituitarism in 25–50%; in a radiosurgery series of 278 patients followed for 5.6 years, control was 80% and durable control 57% [24]. The Endocrine Society recommends confirming the efficacy of medical therapy before radiotherapy and measuring cortisol off medication every 6–12 months afterwards [2].

Bilateral adrenalectomy in CD and ectopic secretion. It is indicated in occult or metastatic ectopic secretion, as an emergency measure and as a last resort in CD [2, 24]. In a review of 23 studies with 739 patients, surgical morbidity was 18% and median mortality 3% (<1% in CD); residual cortisol from accessory tissue occurred in 3–34%, recurrence of CS in <2% and adrenal crises at 9.3 per 100 patient-years; 10-year mortality was 3% in CD, 10% in bilateral adrenal hyperplasia and 44% in ectopic secretion [2]. Nelson syndrome occurred in 21% of adults operated on for CD, with progression of the corticotroph tumour on MRI in 50% [2]; the 2021 consensus gives progression of 25–40% at 5–10 years and recommends ACTH and MRI from 6 months [24]. Because it is not influenced by pregnancy, it is preferable in women planning an immediate pregnancy [24].

ACC. Surgery is performed by experienced surgeons, with en bloc resection, after multidisciplinary discussion and endocrine assessment; adjuvant mitotane is suggested with a high risk of recurrence (European Network for the Study of Adrenal Tumors, ENSAT, stage III, R1 resection or Ki67 >10%) [25]. Operated patients with hypercortisolism receive perioperative hydrocortisone [25].

7.3 Medical therapy: indications and strategy

Medical therapy has four indications: second line after non-curative TSS in CD (with or without radiotherapy), first line in occult or metastatic ectopic secretion, adjuvant in ACC and pre-operative control when surgery is delayed or there are severe complications [2, 24]. In genetic bilateral adrenal disease it is also a lifelong alternative to surgery [5, 115]. Steroidogenesis inhibitors are the first choice when cortisol needs to be normalised quickly: osilodrostat and metyrapone act within hours, ketoconazole within days and intravenous etomidate in very severe cases; in mild CD with residual tumour, pasireotide or cabergoline may be preferred [24]. The order of efficacy in normalising UFC described in the consensus is osilodrostat > metyrapone > ketoconazole > pasireotide > cabergoline [24]. Pituitary-directed drugs are generally ineffective in adrenal causes [2]. There are two strategies: titration until cortisol normalises, or “block and replace”, with complete blockade and replacement hydrocortisone, preferable in severe, cyclical or difficult-to-control disease [2, 26]. Changing drug is recommended if cortisol remains raised after 2–3 months at the maximum tolerated dose [24].

The 2026 review proposes adjusting intensity to the degree of hypercortisolism: with mean UFC <5 times the ULN, slow titration from minimal doses with monitoring every 2–3 weeks; with 5–10 times without complications, high doses from the start with monitoring every 5–7 days or block and replace; above 10 times or with complications, very high doses of osilodrostat or metyrapone, or the combination of ketoconazole with metyrapone, block and replace and titration every 2–3 days, frequently as an inpatient [26]. Sex also matters: ketoconazole reduces androgens (useful in women with hyperandrogenism and to be avoided in men with hypogonadism), whereas metyrapone and osilodrostat increase them [26].

7.4 Drugs and doses

The reference dose is that of the guidelines and expert review; the label dose is given alongside for comparison, noting when the guideline dose lies outside the label conditions. In severe hypercortisolaemia, the Endocrine Society note allows the starting dose to be doubled when UFC is >5 times normal [2].

ICU: intensive care unit; BP: blood pressure.

Osilodrostat. In the LINC-3 trial, hypocortisolaemia occurred in ~half of the patients and required glucocorticoid in 36%; precursor effects (hypokalaemia, hypertension) in 42% and hirsutism in 11% of women [24]. Before starting, potassium and magnesium are corrected and an electrocardiogram is performed at baseline and in the first week; the drug is stopped if the corrected QT interval (QTc) exceeds 480 ms; hypocortisolaemia may persist after discontinuation [116]. The response has a delayed effect of ~3 weeks, a reason not to accelerate titration in non-severe disease, and a single late-afternoon dose is possible in controlled patients [26]. Cortisol measurement should use LC-MS/MS or a highly specific immunoassay, because of cross-reaction with 11-deoxycortisol [26]. The label has no contraindications other than hypersensitivity, but the 2026 review considers it contraindicated in pregnancy, in children and in adolescents for lack of data [26, 117].

Metyrapone. Adverse effects are hypertension (up to 48%), oedema (3–23%), hypokalaemia (7–14%) and hirsutism or acne (5–71%), owing to accumulation of mineralocorticoid and androgenic precursors; the target is normal UFC or a mean serum cortisol of 150–300 nmol/L across the day [2, 26]. Clearance is not altered in renal or hepatic impairment up to cirrhosis, and phenytoin and phenobarbital accelerate its metabolism [2, 26]. It is contraindicated in overt primary adrenocortical insufficiency [118].

Ketoconazole. Severe idiosyncratic hepatotoxicity occurs in ~1 in 15,000 exposed individuals; mild elevation of transaminases occurs in 10–15% and allows treatment to continue if <3 times the ULN [2]. The European SmPC requires liver enzymes and bilirubin before starting, not starting with enzymes >2 times the ULN, weekly monitoring in the first month, monthly for 6 months and weekly for one month after each increase; with enzymes <3 times the ULN the dose is reduced by at least 200 mg/day and with ≥3 times it is permanently discontinued [120]. The drug requires gastric acidity (avoid antacids and proton pump inhibitors), prolongs the QTc, causes male hypogonadism and has extensive interactions through CYP3A4 inhibition; the SmPC contraindicates it in pregnancy and breastfeeding and with CYP3A4-metabolised statins, eplerenone, methadone, quinidine, dronedarone, pimozide, dabigatran, oral midazolam, triazolam, alprazolam, quetiapine and lurasidone, among others [26, 120]. In the paediatric experience described in the SmPC (24 patients), there were 2 cases of severe hepatotoxicity, including the death of a 14-year-old girl with CD treated with 200 mg twice daily [120].

Levoketoconazole. The US label has a boxed warning for hepatotoxicity and QT prolongation and contraindicates the drug in cirrhosis, acute or poorly controlled chronic liver disease, baseline transaminases >3 times the ULN, recurrent symptomatic cholelithiasis, previous azole-induced liver injury, baseline QTcF >470 ms or long QT syndrome [121]. QT prolongation occurred in 5% and transaminitis in the first 8 weeks, reversible; it does not cause male hypogonadism, and the 2026 review concludes that there are no major advantages over ketoconazole [26].

Pasireotide. Hyperglycaemia occurs in ~70–75%, and half of patients need new or adjusted antidiabetic drugs; before starting, glucose, glycated haemoglobin, liver tests, electrocardiogram, gallbladder ultrasound, potassium and magnesium are assessed, with reassessment at 3–4 months [2, 24, 122]. The response is better with UFC ≤5 times the ULN, and tumours with mutated USP8, smaller and with more SSTR5, may respond better [24, 26]. It is not recommended in children [24].

Cabergoline. It may cause impulse control disorders and should be avoided in bipolar disorder; an echocardiogram is recommended at baseline and every 2–5 years [24, 26].

Mifepristone. It has no response biomarker, because cortisol rises; ACTH increased more than 2-fold in 31 of 43 patients with CD and 3 macroadenomas grew [2]. It causes hypokalaemia (treated with spironolactone), endometrial thickening and vaginal bleeding; adrenal insufficiency is treated by discontinuation and dexamethasone 2–8 mg/day [2, 26]. The label has a boxed warning for termination of pregnancy and contraindicates combination with simvastatin, lovastatin and CYP3A substrates with a narrow therapeutic index [124].

Mitotane. Onset is slow, discontinuation due to adverse effects reaches 28–29%, with gastrointestinal effects in 47% and neurological effects in 30%; it increases corticosteroid-binding globulin and induces CYP3A4, so replacement hydrocortisone has to be increased (by one third according to the Endocrine Society; 2–3-fold according to the 2021 consensus) and dexamethasone should be avoided [2, 24, 26]. Plasma levels are measured every 3–4 weeks until a plateau and then every 6–12 weeks, as a morning trough ≥12 h after the last dose; severe neurotoxicity occurs above 20 mg/L [25, 125]. The US label has a boxed warning for adrenal crisis in shock, severe trauma or infection; it is teratogenic and pregnancy should be postponed until 5 years after the end of treatment [26, 125].

Etomidate. It requires ICU monitoring, with cortisol every 4–6 h; the usual doses of 0.04–0.05 mg/kg/h rarely sedate (anaesthesia uses 0.2–0.4 mg/kg/h); formulations with propylene glycol cause thrombophlebitis, haemolysis, tubular injury and lactic acidosis and should be given centrally; the dose is reduced in renal failure [2, 24, 26]. In a review of 76 cases, 80.9% survived to definitive treatment [26].

Combinations. Ketoconazole with metyrapone normalised UFC at one month in 73% of 14 patients with ectopic secretion and 86% of 8 with ACC; the triple regimen of mitotane 3.0–5.0 g/day, metyrapone 3.0–4.5 g/day and ketoconazole 400–1200 mg/day controlled 64% of 11 critically ill patients, with hypokalaemia in all [2, 26]. In CD, pasireotide with cabergoline or ketoconazole with cabergoline are described combinations; in the CAPACITY trial, pasireotide with or without cabergoline normalised UFC in 37.9% at week 35 [24, 26].

The French PNDS has its own table of indicative dosages, which generally coincides with the reference and diverges in some maxima (section 7.17).

SST2: somatostatin receptor type 2.

The protocol adds safety details. Ketoconazole raises liver enzymes in 5–10%, requires weekly enzymes in the first month and after each increase, an electrocardiogram before and during treatment, is contraindicated with CYP3A4-metabolised statins, dabigatran, alprazolam and methadone, and CYP3A4 inducers reduce its efficacy [22]. Osilodrostat (half-life ~4 h, versus ~2 h for metyrapone) may cause delayed adrenal insufficiency, which is prevented with therapeutic education and an individual adrenal insufficiency card, and requires an electrocardiogram before and after initiation and correction of hypokalaemia, hypocalcaemia and hypomagnesaemia [22]. Mitotane leads 30% of patients to stop because of digestive and neurological intolerance, has a therapeutic index of 14–20 mg/L in ACC with neurotoxicity above 20 mg/L, and pregnancy is proscribed while the drug is detectable in plasma [22]. Pasireotide acts on SST5, highly expressed in 30% of corticotroph tumours, is effective in about half of moderate hypercortisolism cases, may shrink the adenoma and causes hyperglycaemia, gallstones and, rarely, syncope and long QTc [22]. Mifepristone causes hypokalaemia in one third, sometimes severe, and endometrial thickening in 20% of women [22]. The protocol describes combinations of steroidogenesis inhibitors and that of pasireotide, cabergoline and ketoconazole, whose safety has not been systematically studied, somatostatin analogues in ectopic tumours with SST2 and, in medullary thyroid carcinoma with ectopic ACTH secretion (a tumour that may arise in MEN2), vandetanib and sorafenib, with a direct antisecretory effect [22]. Under metyrapone, osilodrostat and etomidate, accumulation of 11-deoxycortisol falsifies certain cortisol immunoassays through cross-reaction, which indicates LC-MS/MS; under mitotane, the increase in corticosteroid-binding globulin raises total cortisol with any technique, including LC-MS/MS [22]. Because these patients take multiple medications, the PNDS recommends medication reconciliation on admission and discharge, by trained professionals in a multidisciplinary team, with a formal link between hospital and community care [22].

7.5 Therapy directed at PBMAH and aberrant receptors

The Endocrine Society suggests therapy that blocks aberrant hormone receptors in BMAH when these are demonstrated [2]. In practice, the response to these drugs is partial or transient and surgery remains the definitive treatment [5]. The table summarises the options described in the 2023 review, with the level of evidence in PBMAH.

LH/hCG: luteinising hormone and human chorionic gonadotrophin; SC (route): subcutaneous.

In ARMC5 carriers there is no gene-directed treatment; the decision follows the degree of hypercortisolism and comorbidities [2, 5]. In KDM1A carriers, unilateral adrenalectomy is favoured and cortisol synthesis inhibitors or aberrant receptor blockers are used less often [5, 11]. In MACS with bilateral lesions, contraindication to or refusal of surgery, the 2026 review describes low doses of metyrapone (500 mg at 18 h and 250 mg at 22 h, n=6, with normalisation of the rhythm), ketoconazole (200–400 mg/day, one patient with bilateral macronodular hyperplasia) and mifepristone (200 mg twice daily for 4 weeks or 300 mg/day for 6 months), with improvement in glucose, BP and weight [26]. These doses come from small series and lie outside the dose conditions of the labels. Adjusting the dose to the rhythm, with higher doses at night, and the block-and-replace regimen in the cyclical form are described options; trilostane partially suppressed without halting growth, and mitotane is rarely used [5].

7.6 Neonatal Cushing in McCune-Albright syndrome

Guidelines are difficult to establish because of rarity, and infants are frequently critically ill at presentation [18]. The GeneReviews algorithm (figure 16, consulted) indicates metyrapone as first line because of its low hepatotoxicity, with a starting dose of 300 mg/m²/day in 2 doses, a usual blocking dose of 600 mg/m²/day and a maximum dose of 1200 mg/m²/day; etomidate is reserved for critically ill patients unstable for surgery, in combination with metyrapone, with a starting dose of 0.25 mg and a usual blocking dose of 1 mg/kg (the figure does not specify the time unit of the infusion); mitotane and ketoconazole have little experience in MAS and should be used with caution because of hepatotoxicity [18]. Metyrapone is preferred to ketoconazole in children with liver abnormalities, frequent in MAS [18, 23]. The Portuguese SmPC for metyrapone has no paediatric dosage for the treatment of CS and requires individual adjustment by cortisol and tolerability; the GeneReviews dose therefore lies outside the label conditions [118]. The 2026 review mentions prolonged use of metyrapone suppositories in children, with improvement and without effects on development [26].

In long-term treatment, bilateral adrenalectomy is usually necessary; unilateral adrenalectomy may be considered if the disease is limited to one side on CT, and was described in a 1-year-old boy with asymmetric disease, with normalisation of the ACTH and cortisol rhythm and of UFC [18, 109]. Spontaneous resolution, through involution of the fetal zone, occurred in about one third according to the GeneReviews figure and in 10 of 23 survivors in the NIH series, which justifies surveillance in mild cases, with an individual decision weighing severity, the capacity for medical control and the effect of hypercortisolism on neurodevelopment [18, 23]. The Endocrine Society allows medical therapy in mild cases, because spontaneous remission has been described during pharmacological control, and indicates bilateral adrenalectomy in severe cases with hypertension [2]. Children with a history of hypercortisolism in MAS should be referred for early neurodevelopmental intervention [18].

7.7 Children and adolescents

Surgery is first line in children, as in adults [24]. For medical therapy, the 2021 consensus indicates ketoconazole or metyrapone with monitoring by morning cortisol, block and replace with metyrapone as an option, and does not recommend pasireotide; paediatric osilodrostat trials were under way [24]. Ketoconazole is authorised in the EU from 12 years at adult doses; pharmacokinetics with 5–10 mg/kg/day (≈200–800 mg/day) are similar to those in adults, but hepatotoxicity may be more frequent in adolescents [120]. Osilodrostat, pasireotide, levoketoconazole and mifepristone have no established safety and efficacy below 18 years [116, 117, 121, 123, 124]. Paediatric mitotane is started at 1.5–3.5 g/m²/day with a target of 4 g/m²/day, with caution when levels reach 10 mg/L [126]. Thromboprophylaxis is not given routinely in children because of the bleeding risk [24]. After cure, adrenal recovery takes ~12 months, GH deficiency should be assessed at 3–6 months and treated immediately, and obesity does not fully reverse [24]; GH deficiency persists in more than half of children in the first 12 months and final height is frequently below the genetic target [2].

The French PNDS adds that drug therapy in children is decided only case by case at a national multidisciplinary consultation meeting, that the drugs have not been evaluated in paediatrics (neither in CD nor in the post-operative treatment of ACC) and that, in France, metyrapone is the only drug with a marketing authorisation for all causes of CS and all ages, whereas ketoconazole is authorised from 12 years, osilodrostat and pasireotide only in adults and cabergoline has no established safety below 16 years [22]. In children, the protocol recommends calcium supplementation if dietary intake is below 300 mg/day, systematic vitamin D of 800–1600 IU/day, densitometry during follow-up from 5 years, GH assessment 3 months after TSS or radiotherapy and transient GH treatment, frequently indicated by growth delay and the latency of somatotroph recovery [22].

7.8 Pregnancy and lactation

About 300 pregnancies with CS have been described, with pre-eclampsia, gestational diabetes and maternal–fetal morbidity; active treatment reduces fetal losses [26]. In mild cases comorbidities are treated, low-molecular-weight heparin (LMWH) is used and definitive treatment is postponed until after delivery; in severe cases, surgery (pituitary or, more often, adrenal) is performed in the second trimester, before 24 weeks [26]. No drug is approved in pregnancy; metyrapone (500–3000 mg/day) and cabergoline are the preferred options, with a serum cortisol target of 2–3 times the ULN and UFC of ~1.5 times the ULN [24, 26]. Ketoconazole is less safe (feminisation of the male fetus, especially in the first trimester) and is contraindicated in the SmPC, as in breastfeeding; osilodrostat, pasireotide and levoketoconazole have no experience; mitotane and mifepristone are contraindicated [26, 120, 124]. Metyrapone crosses the placenta, requires monitoring of BP and pre-eclampsia and, in the newborn, of cortisol and electrolytes at birth and in the following week; it is excreted in milk [2, 118]. Osilodrostat requires a pregnancy test, effective contraception until at least 1 week after the last dose and suspension of breastfeeding during that period [117]. During active CS and medical therapy, oestrogen-free contraception is recommended [26]. The 2025 Delphi consensus considers pregnancy and the puerperium up to 6 weeks risk factors that justify thromboprophylaxis and generally recommends prophylactic anticoagulation throughout pregnancy, whatever the cortisol level (section 7.10) [129]. For suspected ACC in pregnancy, the European guidelines recommend immediate resection in any trimester [25]. Unilateral adrenalectomy in PPNAD is discussed as a way of preserving fertility and a safer perinatal course [34], and CNC may be associated with a higher risk of miscarriage and reduced male fertility [19].

The French PNDS describes diagnosis in pregnancy, with fewer than 300 cases published between 1952 and 2020. It is suspected in the presence of hypertension or diabetes with facio-truncal distribution, marked striae, limb-girdle amyotrophy, acne, hirsutism or hypokalaemia, and pre-eclampsia, fetal growth restriction and fractures may be revealing [22]. The first test is late-night salivary cortisol, little altered in the first and second trimesters; absence of a circadian rhythm is always pathological and UFC above 3–4 times the ULN is generally pathological at any stage, whereas midnight serum cortisol and the DST cannot be used [22]. For the cause, ACTH and adrenal ultrasound are performed (a negative ultrasound does not exclude a tumour), unenhanced adrenal MRI if ACTH is undetectable or low and unenhanced pituitary MRI if it is normal or high, preferably after the first trimester; dynamic tests are not performed, IPSS is not recommended and, unlike outside pregnancy, an adrenal cause is the most frequent [22]. If gadolinium is needed, the patient is informed of the benefit–risk balance and gadobenate (MultiHance®) or gadoteridol (ProHance®) is preferred [22]. In treatment, symptomatic control is central and was the only treatment in some slowly progressive CD cases; TSS is discussed mainly in the second trimester, ACC justifies prompt surgery and an adenoma can wait if symptomatic treatment is effective, although histological uncertainty and severity may lead to surgery during pregnancy [22].

7.9 Severe hypercortisolism and emergency

Urgent treatment (24–72 h) is indicated in the presence of life-threatening complications [2]. In severe hypercortisolism, the 2026 review indicates oral osilodrostat (10–20 mg/day with +10 mg/day every 72 h) or metyrapone (1500 mg/day with +750 mg every 72 h up to 3750 mg/day), with or without ketoconazole (800 mg/day with a rapid increase to 1200 mg/day in combination), and intravenous etomidate in the ICU when there is no oral route or severity requires it [26]. Prophylaxis of Pneumocystis jirovecii pneumonia with co-trimoxazole (800/160 mg three times weekly or 400/80 mg/day) and anticoagulation are indicated particularly in bedridden patients or those with UFC >5 times normal [2, 26]. Bilateral adrenalectomy is the rescue measure when optimised medical treatment, including combinations, does not control hypercortisolism [2, 24]. The PNDS generally considers prophylaxis of pneumocystosis with sulfamethoxazole-trimethoprim (Bactrim® in France) necessary when starting treatment of severe CS, and reserves etomidate for the ICU [22].

7.10 Thromboprophylaxis, comorbidities and vaccination

The risk of spontaneous VTE in CS has an odds ratio of 17.82 (95% CI 15.24–20.85) in a review of 48 studies with 7142 patients, and 45% of episodes occur in the 6 months after surgery [26]. The population studies brought together by the 2025 Delphi consensus quantify the risk at several time points: in the Dutch national cohort, the incidence of VTE was 14.6 per 1000 person-years (95% CI 10.3–20.1), versus 1–2 in the general population, already 14.1 before treatment, and the risk in the 3 months after surgery was 3.4% (95% CI 2.0–5.9) in ACTH-dependent CS; in the Danish population of 1980–2010, the hazard ratio was 2.6 (95% CI 1.5–4.7), with an excess already present 3 years before diagnosis and of 20.6 (95% CI 7.8–53.9) in the year after diagnosis; in the Swedish registry, the standardised incidence ratio of deep vein thrombosis was 13.8 in the 3 years before diagnosis, 18.3 from diagnosis to 1 year after remission and 4.9 in prolonged remission [129]. The risk of VTE after adrenalectomy for CS was 2.6% in a retrospective series, the pooled incidence after TSS for CD was 2%, surgical reintervention had a hazard ratio of 2.18 (95% CI 1.38–3.45) in the European ERCUSYN registry, and most studies found no relationship between the intensity of hypercortisolism measured by UFC and the risk of VTE [129]. The procoagulant state results from increased factor VIII, von Willebrand factor, fibrinogen and plasminogen activator inhibitor type 1, with reduced fibrinolysis, and may take up to 1 year to normalise after surgery [129].

The 2025 Delphi consensus, promoted by Endo-ERN with 18 experts from 11 countries and defined by agreement ≥75%, is the first position statement dedicated to the topic and formulated 14 recommendations [129]. LMWH doses are the standard weight-adjusted prophylactic doses of each country, with adjustment in obesity and renal failure decided by the responsible endocrinologist or haematologist; the consensus does not specify a molecule or a dose [129].

BMI: body mass index.

In practice, the consensus describes the perioperative period as follows: prophylactic LMWH before surgery, with the last dose 24 h beforehand; restart 24 h after surgery and maintenance until 3 months after normalisation of cortisol and mobilisation, normalisation meaning post-operative serum cortisol <5 µg/dL (<138 nmol/L) or <2 µg/dL (<50 nmol/L) after TSS, hypocortisolism with physiological-dose replacement or normal UFC under medical therapy [129]. At IPSS, prophylactic LMWH is continued; therapeutic-dose LMWH is stopped 24 h before and resumed 48 h after, with a prophylactic dose in the interval; direct oral anticoagulants (DOAC) are stopped 24–72 h before and resumed 48 h after, with prophylactic LMWH in the interval; in patients without prophylaxis, prophylactic LMWH is started 12 h after the procedure [129]. In the event of VTE, LMWH is the preferred initial therapy when the event occurs in the first 6 post-operative weeks, because of the possible need for reintervention; outside that period LMWH or DOAC at therapeutic dose may be used, according to the general VTE guidelines [129]. DOAC as prophylaxis in CS is off-label use, without safety data in this population and with a reported bleeding risk higher than with LMWH; the proposal to prefer them where available had 41% agreement [129]. Mitotane alters haemostasis and liver function and, combined with LMWH, increases the bleeding risk, which requires monitoring of bleeding, renal function and platelets and possible adjustment of the LMWH [129]. Factors that increase bleeding risk include active bleeding, acquired bleeding disorder (such as liver failure), other anticoagulants, acute stroke, platelets <75 × 10⁹/L, BP >200 mmHg systolic or >120 mmHg diastolic, untreated hereditary bleeding disorders and recent or planned surgery; severe thrombocytopenia, advanced liver disease, heparin-induced thrombocytopenia and renal failure require an individual decision [129]. In pregnancy with CS, prophylactic anticoagulation throughout gestation is generally recommended, whatever the cortisol level [129]. In mild CS and MACS there was insufficient evidence to recommend (the proposals obtained 41–59% agreement), and the optimal duration after cure and the role of DOAC remained research priorities [129].

The 2021 consensus recommends early ambulation and compression stockings and suggests LMWH in at-risk patients, with a post-operative duration of 1–2 days to 2–3 months [24]. In hypertension, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are first line, with a target ≤130/80 mmHg and spironolactone in hypokalaemia [26]. Bisphosphonates are recommended in persistent CD even with normal bone mineral density, FRAX is not validated and physical rehabilitation is recommended for all [24].

The French PNDS details the prevention of complications. For the skin, trauma and irritation are avoided, lesions are treated early (with a dermatologist or burns specialist if necessary), sun protection factor 50+ is used, hirsutism is treated and gastroduodenal ulcers are prevented with proton pump inhibitors (off-label in primary prevention) [22]. For muscle, maintenance physiotherapy is given in the severe phase and muscle strengthening afterwards [22]. For bone, falls are prevented, tobacco, alcohol and excess salt are avoided, a calcium intake of 800–1200 mg/day with monitoring of urinary calcium and a 25-hydroxyvitamin D above 30 ng/mL (75 nmol/L) are ensured, and oestrogen–progestogen or androgen replacement is not given during hypercortisolism, because of the thrombotic risk; by analogy with glucocorticoid-induced osteoporosis, a bisphosphonate or teriparatide (off-label, with a rheumatologist) is considered in the presence of an osteoporotic fracture or a T-score ≤−2.5 at the spine or total hip, with prior dental examination because of the risk of osteonecrosis of the jaw, without teriparatide in young patients, with experience limited to 2 years for bisphosphonates and 36 months for teriparatide, and with follow-up densitometry at 1 year if hypercortisolism persists without bone treatment [22]. For metabolism, diabetes and dyslipidaemia are treated (statins, fibrates, ezetimibe) with enhanced liver monitoring if combined with ketoconazole or mitotane, and treatment is adjusted rapidly after correction of CS [22]. In hypertension, a low-salt diet and correction of hypokalaemia are recommended, with spironolactone (or eplerenone) preferred in hypokalaemia, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, which control BP in ~50%, beta-blockers before surgery in patients at high cardiovascular risk and monitoring of hypokalaemia and hypercalciuria under furosemide [22]. For thrombosis, support stockings or intermittent pneumatic compression with early mobilisation are advised, and anticoagulation is decided case by case perioperatively (adrenalectomy, TSS, IPSS), in intense hypercortisolism or reduced mobility, maintained for more than 4 weeks after surgical correction of CS [22]. For global cardiovascular risk, antiplatelet aspirin is left to the decision of the endocrinologist or cardiologist, also taking account of vascular fragility, with dissections of large vessels described [22]. For infections, tuberculosis prophylaxis is proposed in untreated past tuberculosis or recent contact with contagious tuberculosis, and pneumococcal and influenza vaccination is discussed case by case; when starting treatment of severe CS, the protocol often considers prophylaxis of pneumocystosis with sulfamethoxazole + trimethoprim (Bactrim®) necessary [22]. The Endocrine Society mentions the same prophylaxis (dapsone in sulfonamide allergy), particularly in bedridden patients or those with UFC >5 times the ULN [2]. For the endocrine axes, gonadal replacement is not given in the acute phase, gonadotrophins are used to restore fertility in gonadotrophin deficiency, GH follows the authorised indications and thyrotroph or posterior pituitary replacement is given after pituitary surgery when there is a deficiency [22]. In psychiatry, assessment by a psychiatrist is often necessary, with anxiolytics, hypnotics, neuroleptics, antidepressants or electroconvulsive therapy according to the clinical picture; the response to selective serotonin reuptake inhibitors may be transient, depression and cognitive deficits may persist after cure, and complementary psychotherapies (cognitive-behavioural, supportive, psychodynamic) are provided by hospital or community psychologists [22]. Plastic and reconstructive surgery (abdominal wall, breast, gynaecomastia, keloids) is performed at a distance from CS, informing the patient of the risk of pigmented scars in melanoderma and communicating the patient’s adrenocortical status to the anaesthetist and surgeon [22].

7.11 Perioperative care, glucocorticoid replacement and recovery of the axis

After surgical remission, glucocorticoid replacement and education about adrenal insufficiency are mandatory [2]. The Endocrine Society recommends hydrocortisone 10–12 mg/m²/day in 2–3 doses, the first on waking; supraphysiological doses have no controlled studies [2]. In the block-and-replace regimen, the 2026 review uses hydrocortisone 15–20 mg/day in 2–3 doses or prednisolone 3–5 mg/day [26]. After bilateral adrenalectomy, gluco- and mineralocorticoid replacement is lifelong [2]. For fludrocortisone, the CS guidelines consulted give no dose; the US label, for replacement in primary adrenal insufficiency (analogous condition), indicates 0.1 mg/day (range 0.1 mg three times weekly to 0.2 mg/day), reducing to 0.05 mg/day if hypertension develops, combined with hydrocortisone 10–30 mg/day in divided doses, and does not establish safety and efficacy in children [130]. In the adolescent in the case in section 10, hydrocortisone 8 mg/m²/day (5–5–2.5 mg every 8 h) and fludrocortisone 0.1 mg/day were used after bilateral adrenalectomy [38]. The patient on replacement should increase the dose during illness or stress, carry an emergency kit with injectable glucocorticoid and start the glucocorticoid themselves in moderate or severe adrenal insufficiency before contacting the team [26, 85].

Recovery of the axis takes 6–12 months after resection of ACTH-producing tumours and ~18 months after unilateral adrenalectomy (12.6 ± 3.3 months in a paediatric series); it is assessed with morning cortisol before the dose every 3 months, an ACTH test when cortisol is ≥7.4 µg/dL (200 nmol/L), and the axis is considered recovered with basal or stimulated cortisol ≥18 µg/dL (500 nmol/L); with <5 µg/dL (138 nmol/L) replacement is continued and testing is repeated in 3–6 months [2]. Glucocorticoid withdrawal syndrome (anorexia, nausea, myalgia, arthralgia, desquamation, depression) may last more than a year [2]. Osilodrostat may cause prolonged adrenal insufficiency after discontinuation (7 cases lasting 1.4 to 36 months) [26]. Before adrenal surgery in a patient with MEN1, urinary catecholamines should be measured to exclude phaeochromocytoma [13].

The PNDS refers replacement to the consensus statements of the Société Française d'Endocrinologie and the Société Française d'Endocrinologie et Diabétologie Pédiatrique (oral or parenteral hydrocortisone and fludrocortisone after bilateral adrenalectomy), draws attention to the withdrawal syndrome with asthenia and pain after rapid correction, and gives priority to therapeutic education about adrenal insufficiency after bilateral adrenalectomy or under potent anticortisol drugs; the reference and competence centres provide an adrenal insufficiency card [22]. Criteria for cure vary: morning cortisol <50 nmol/L (18 µg/L) in the strict definition, or a normal cortisol profile or UFC in the less demanding definition, in both cases with disappearance of the clinical signs [22].

7.12 Agents to avoid and interactions

During investigation, oral oestrogens should be avoided before the DST and the drugs that alter dexamethasone metabolism should be known [1]. With ketoconazole and levoketoconazole, proton pump inhibitors and antacids and drugs that prolong the QT or are sensitive CYP3A4 substrates are avoided [120, 121]. With mifepristone, simvastatin, lovastatin and narrow-index CYP3A substrates are avoided, warfarin is reduced and it is not used in patients who need vital systemic corticosteroids [26, 124]. With mitotane, dexamethasone should be avoided and hydrocortisone has to be increased [2]. Ketoconazole should be avoided with transaminases >3 times the ULN and in men with hypogonadism; cabergoline, in bipolar disorder or with impulse control disorder [24, 26].

7.13 Transition to adulthood

The Endocrine Society and Pituitary Society guidelines do not describe formal transition protocols for this class; the French PNDS proposes its own scheme. The elements to transfer are the same as those of the underlying syndromes: adrenal replacement and emergency plan, surveillance of CNC, MEN1, Li-Fraumeni syndrome or MAS (section 11), reproductive counselling and, in patients with adrenalectomy in childhood, assessment of growth, puberty and GH deficiency [2, 19, 24].

According to the PNDS, preparation begins at around 12–14 years and lasts until one year before transfer, with information about the conditions, progressive empowerment (assessment of knowledge, gradual withdrawal of the parents, questionnaire, reinforcement of therapeutic education on medication and administrative procedures) and early identification of the adult specialist and family doctor; transfer takes place between 16 and 20 years (at around 18 years or at the end of puberty), ideally during a period of clinical, psychological and social stability, with one or two joint or alternating consultations within less than a year, prior sending of a summary, results and liaison form, a report of each consultation to the family doctor and paediatrician and the possibility for the paediatrician to recontact the young person if follow-up fails [22].

7.14 Comparative regulatory status

T2DM: type 2 diabetes mellitus; CHMP: EMA Committee for Medicinal Products for Human Use; PDUFA: Prescription Drug User Fee Act.

7.15 Main trials

OR: odds ratio; AUC: area under the curve.

These trials do not allow indirect comparison between drugs: they differ in population (CD only, CS of any cause, mild hypercortisolism), in design (randomised withdrawal, single arm, placebo control) and in the definition of response. Randomised withdrawal designs (LINC-3, LOGICS, GRACE) include only responders from the open-label phase and measure maintenance, not initial efficacy [24]. No trial specifically included patients with an identified genetic cause or children, and the only paediatric osilodrostat study (NCT03708900, phase 2, 12 patients planned) was recruiting, without results, with completion expected in 2027 [139]. GRADIENT, in the adrenal population, did not meet its primary endpoint, although the sponsor states that the FDA considered it confirmatory evidence [134, 138]. The CATALYST data come from the sponsor, with no peer-reviewed publication located [135]. The ClinicalTrials.gov search identified no therapeutic trials directed at PBMAH, KDM1A, CNC or Cushing in MAS, only completed NIH natural history studies; a negative search does not prove non-existence [139].

7.16 Developments in the last 12 months

The regulatory and scientific developments between October 2025 and October 2026 are as follows, with the level of evidence of each. In regulation (official sources): the US osilodrostat label was updated on 2025-11-18, after extension to CS of any cause (2025-04-15) [116, 131]; the levoketoconazole label was revised on 2026-03-10 [121]. For relacorilant (sponsor press release and reports to the Securities and Exchange Commission, SEC): the FDA issued a CRL on 2025-12-30 for hypertension secondary to hypercortisolism, acknowledging that GRACE met its primary endpoint but without a favourable benefit–risk assessment; the application was resubmitted on 2026-06-17 with a decision date of 2026-12-17 [134, 135]. In peer-reviewed publications: the prospective PROMPT trial of metyrapone [136]; the Delphi consensus on thromboprophylaxis [129]; the international cohort of cyclical CS [107]; the review with practical dose recommendations [26]; the ENSAT Kids Delphi consensus on paediatric ACC, read only in abstract [140]; the São Paulo PPNAD cohort [83]; the familial PDE11A case [38]; and the estimate of ARMC5 and KDM1A carriers in gnomAD [141]. In the development phase (early human studies cited by the 2026 review): atumelnant (oral MC2R receptor antagonist; phase 1b/2, NCT05804669) normalised UFC in 5 patients with ACTH-dependent CS after 80 mg for 10 days; the anti-ACTH antibody LuAg13909 is in phase 2; clofutriben (11β-hydroxysteroid dehydrogenase type 1 inhibitor) was studied in a randomised trial; seliciclib (400 mg twice daily, phase 2 with 9 women) reduced UFC by 42% without normalisation and with grade 4 liver toxicity in 2; gefitinib was studied in CD with mutated USP8 (NCT02484755); USP8 inhibitors and the GIPR antagonist are preclinical [5, 26, 142].

7.17 Divergences between sources

The recommendations differ on several points. In PBMAH, the 2015 Endocrine Society guideline recommended bilateral adrenalectomy as the surgical treatment of choice, whereas the 2023 review and the 2023 European guidelines favour unilateral adrenalectomy of the larger gland and advise against bilateral adrenalectomy without overt CS, accepting the higher recurrence rate [2, 5, 79]. For screening relatives of ARMC5 carriers, the 2015 Endocrine Society guideline proposed the DST “until genetic testing becomes available”, now replaced by testing for the familial variant [2, 5]. The Endocrine Society maximum ketoconazole dose of 1600 mg/day exceeds the maximum of 1200 mg/day in the European SmPC and the 2021 consensus [2, 24, 120]. The increase in hydrocortisone under mitotane is one third in the Endocrine Society guideline and 2–3-fold in the 2021 consensus [2, 24]. Thromboprophylaxis has moved from a perioperative suggestion (Endocrine Society 2015) to consideration from diagnosis until 3 months after remission (Delphi 2025), with the 2021 consensus in an intermediate position [2, 24, 129]. The 2021 consensus includes compression stockings among the recommended measures, whereas the 2025 Delphi advises against them in CS (87% agreement) for lack of benefit and skin risk [24, 129]. The frequency of spontaneous resolution of Cushing in MAS is “about half of survivors” in the GeneReviews text and “about one third” in its figure 16, and was 10 of 23 survivors in the NIH series [18, 23]. Between labels, osilodrostat titration is slower in the FDA label (minimum interval of 2 weeks) than in the EMA label (1–2 weeks), and the starting dose of subcutaneous pasireotide may be 0.9 mg only in the USA [116, 117, 122, 123]. As to the prognostic value of USP8 in CD, the 2021 consensus accepts that it may predict recurrence, whereas Ma’s Chinese series found no difference in the rate or time to recurrence [24, 55].

The French PNDS adds its own divergences. The incidence it gives (1.2–5 per million per year) has wider limits than that of the 2023 review (1.8–3.2) [5, 22]. It gives PPNAD in ~60% of patients with CNC, versus ~25% in one passage of GeneReviews and 70% of women and 45% of men in another; the difference depends on whether PPNAD with Cushing or histological PPNAD is counted and on the origin of the series [19, 22]. The paradoxical rise in UFC with dexamethasone appears in 38% of operated PPNAD in the PNDS and in 70% of the series of 13 patients described in OMIM [22, 33]. In pseudo-Cushing, UFC does not exceed 4 times the ULN in the PNDS and generally 3 times in the Endocrine Society guideline [1, 22]. In pregnancy, the PNDS considers UFC above 3–4 times the ULN pathological at any stage, whereas the Endocrine Society applies the 3-fold threshold to the second and third trimesters [1, 22]. In CD in remission, the PNDS repeats the assessment annually for at least 10 years, and the 2021 consensus proposes lifelong annual surveillance [22, 24]. For thromboprophylaxis, the PNDS advises support stockings or pneumatic compression and case-by-case anticoagulation maintained for more than 4 weeks after correction, whereas the 2025 Delphi advises against stockings and proposes LMWH until 3 months after remission [22, 129]. Pneumococcal and influenza vaccination is discussed case by case in the PNDS and recommended by the Endocrine Society [2, 22]. On adrenal CT, the PNDS accepts as benign a homogeneous lesion ≤30 mm with ≤20 HU or ≤40 mm with ≤15 HU, whereas the 2023 European guideline limits that status to ≤10 HU and requires additional imaging or follow-up at 12 months between 11 and 20 HU [22, 79]. In doses, the cabergoline maximum (4 mg/week) is lower than the 7 mg/week of the series cited in the 2026 review, the mifepristone range (200–1000 mg/day) starts below the starting dose of the US label, mitotane reaches 8–9 g/day with plasma levels and the high dose of etomidate (0.5–1 mg/kg/h) exceeds the maximum of 0.3 mg/kg/h in the review; the reference remains the doses in the main table of section 7.4 [22, 26, 124]. As to status, the PNDS gives metyrapone as authorised in France at all ages, whereas the Portuguese SmPC has no paediatric dosage for the treatment of CS [22, 118].

8. Reproductive Options and Family Counselling

8.1 Recurrence risks by mechanism

Counselling depends on whether the defect is germline, post-zygotic or somatic, and this distinction is the first information to give the family. The table summarises the scenarios.

8.2 Cascade and predictive testing

In PBMAH, AD inheritance justifies offering testing for the familial variant to all adult first-degree relatives of carrier index cases; in a multicentre study, screening of 8 first-degree relatives of 3 index cases identified 4 carriers [5, 10]. Relatives of index cases without an identified variant undergo clinical examination and DST, especially above 50 years [5]. The sources on PBMAH address testing in adult relatives and do not define a paediatric age for predictive testing, consistent with onset in adulthood [5]. In CNC, testing for the familial variant identifies the carriers who need surveillance from childhood, including echocardiography, and the Endocrine Society recommends testing relatives when CNC is confirmed in a patient with PPNAD [2, 19]. In the São Paulo cohort, cascade screening identified 20 carriers, 8 of them asymptomatic with MACS [83]. In MEN4, the paediatric risk is low and predictive testing can be deferred until 18 years, according to the position of the American Society of Clinical Oncology (ASCO) [14]. In Li-Fraumeni syndrome, the risk of ACC begins at birth and predictive testing and surveillance start in childhood [16].

8.3 Interpretation of susceptibility alleles

PDE11A alleles require specific counselling. The frequent missense variants (p.(Arg804His), p.(Arg867Gly)) are present in controls and do not by themselves justify predictive testing or surveillance; rare truncating alleles, such as p.(Arg307Ter), segregate with disease in some families and justify biochemical assessment of carriers [8, 38, 87]. The same principle applies to ARMC5 missense variants, several of which have a population frequency incompatible with pathogenicity [20]. The estimated prevalence of ARMC5 carriers in gnomAD (37.5–64.1 per 100,000) shows that most carriers never reach a diagnosis of PBMAH, because penetrance is incomplete [141].

8.4 Reproductive options

With a known familial variant in PRKAR1A, ARMC5, KDM1A, MEN1 or TP53, prenatal diagnosis and preimplantation genetic testing are technically possible; for CNC GeneReviews mentions them explicitly, and when the cause has not been identified it recommends DNA banking [19]. In MEN1, the Oxford Desk Reference describes prenatal diagnosis by chorionic villus sampling [96]. In forms with adult onset and incomplete penetrance (ARMC5, KDM1A), the decision weighs the treatable severity of the disease and the age at onset. In MAS there is no indication, because the variant is post-zygotic [111]. Pregnancy in a woman with active CS carries maternal and fetal risks and should be planned after control, with oestrogen-free contraception during active disease (section 7.8) [26]. In PPNAD, unilateral adrenalectomy has been proposed to preserve fertility, and CNC may be associated with reduced male fertility [19, 34].

8.5 Counselling of minors

Counselling of minors distinguishes syndromes with paediatric risk (CNC, MEN1, Li-Fraumeni, DICER1), in which testing in childhood has a surveillance benefit, from adult-onset forms (ARMC5, KDM1A, PDE11A), in which the sources consulted describe testing only in adults [5, 13, 15, 16, 19]. In MAS, the family should know that the risk of Cushing is considered nil after 3 years, but that there may be late adrenal insufficiency and neurodevelopmental delay, which justify surveillance [18, 23]. The French PNDS proposes genetic counselling according to the aetiology and family investigation and in all children with CS [22].

9. Special Considerations: Population Diversity and Epidemiology

9.1 What each figure measures

The available estimates measure different things and should not be added together or converted into one another. The table separates incidence and prevalence of disease, proportions in clinical series and carrier frequency.

9.2 United States and Europe

The cohort data for the class come mainly from reference centres in the USA (NIH, for CNC, PRKACA copy gain and MAS) and Europe (French, German and European consortia for PBMAH, CD with USP8 and adenomas with PRKACA) [19, 23, 40, 41, 56, 90]. Bertherat’s series of 185 families with CNC gave the PRKAR1A detection rate of 62% [19, 143], and the French MEN1 registry (GTE, 715 patients, 1956–2008) the frequency of adrenal lesions [94]. The Swedish cohort of 910 Lynch carriers gave the only population estimate of pituitary tumours in that syndrome [99].

9.3 Founder populations and differences by ancestry

The TP53 variant p.(Arg337His) is the main example of a founder effect in the class: it is present in 78–97% of Brazilian children with an adrenocortical tumour, with an identical haplotype in 95% of 22 unrelated patients, and in more than 90% of paediatric adrenocortical tumours in South Brazil [59, 104]. In 30 families of 41 children with an adrenocortical tumour from South Brazil, all 40 tested were carriers, 240 of 695 relatives in the carrier lineage were positive and the penetrance of paediatric adrenocortical tumour was 9.9% [103]. In Paraná, 353 families totalled 1704 carriers, and adrenocortical tumour was the most frequent cancer in carrier children (48 cases) [59]. For ARMC5, carrier frequency in gnomAD is highest in East Asians (111.4 to 173.7 per 100,000) and lowest in the Middle East (0 to 33.0) and in Ashkenazi Jews (6.8 to 27.0); the variant NP_001098717.1:p.(Arg454Trp) is enriched in East Asians and p.(Arg879Trp) in non-Finnish Europeans, and for KDM1A frequency is highest in the Middle East (66.0) and lowest in Finns (6.2) [141]. ARMC5 variants have been described in North and South America, Europe, the Middle East, Asia and in patients of African ancestry [20]. The European SmPC for osilodrostat recommends a reduced starting dose in patients of Asian ancestry [117].

9.4 Portugal and Brazil

In Brazil, in addition to newborn screening for p.(Arg337His), the São Paulo PPNAD cohort (18 index cases) and São Paulo’s participation in the international screening of 301 PBMAH are the sources of genetic data for the class [48, 83]. Alencar and colleagues described a large Brazilian family with PBMAH and a germline ARMC5 missense variant (section 2.7) [46]. Osilodrostat (Isturisa®) has had an active registration since December 2024 and pasireotide in the SC (Upelior®) and LAR (Signifor LP®) formulations; metyrapone, mifepristone and levoketoconazole are not registered, and the mitotane registrations are inactive [127]. In Portugal, metyrapone (Metopirone®) has a national SmPC with an indication for the treatment of endogenous CS; Infomed listed pasireotide LAR as marketed, and osilodrostat and ketoconazole for CS did not appear in the search with the marketing filter [118, 132]. In the sources consulted there are no Portuguese prevalence estimates for the class; one Portuguese case of isolated micronodular disease at 23 months has been described: a girl with ACTH-independent Cushing’s syndrome and morphologically normal adrenals on magnetic resonance imaging, in whom ¹³¹I-NP-59 scintigraphy showed bilateral uptake; after right adrenalectomy, there was no recurrence of hypercortisolism at 3 years of follow-up [144].

9.5 Special populations

Children, pregnant women, patients with cyclical CS and patients with MACS have diagnostic and therapeutic particularities described in sections 5 and 7. Older people with bilateral incidentaloma and MACS are the group in whom PBMAH is most frequently found, and the European guidelines waive the DST in frail patients with limited life expectancy [79]. Men aged ≥60 years, particularly those with diabetes and hypertension, have up to 40% false positives with late-night salivary cortisol [1].

9.6 European networks and patient associations

Endo-ERN (European Reference Network on Rare Endocrine Conditions) is the European reference network for rare adrenal and pituitary diseases, including CS, PBMAH, PPNAD and CNC [27]. For cancer predisposition syndromes (Li-Fraumeni, Lynch) the relevant network is ERN GENTURIS, and for paediatric ACC ERN PaedCan. Patient associations include the Cushing's Support & Research Foundation (CSRF, USA) [145], the Carney Complex Community [146], the Pituitary Foundation (United Kingdom) [147] and the Association for Multiple Endocrine Neoplasia Disorders (AMEND) [96]. In the sources consulted, no Portuguese or Brazilian associations specific to CS were identified.

In France, the PNDS “Syndrome de Cushing” was coordinated by the reference centre for rare adrenal diseases (Hôpital Cochin, Paris) with the competence centres, within the FIRENDO filière for rare endocrine diseases; up-to-date contacts are on the websites of the reference centre and of FIRENDO, which provides documents for patients and questionnaires on the impact on daily life to attach to applications for social support [22]. A confirmed diagnosis gives entitlement to the long-term condition scheme (ALD), with exemption from co-payment [22]. Follow-up takes place in a reference or competence centre or in liaison with one, with the attending physician treating intercurrent illnesses; the centres’ therapeutic education programmes, aimed at pituitary and adrenal diseases, include patients with CS and may involve relatives, associations and expert patients [22]. The patient association is the Association Surrénales, which the protocol recommends introducing from diagnosis; social support includes the Maisons Départementales des Personnes Handicapées, recognition of disabled worker status, the disability compensation benefit and the disabled adult allowance, adaptation of the workstation and working hours (therapeutic part-time work) and the involvement of the occupational or school physician [22].

10. Illustrative Clinical Case

10.1 Published case: familial PPNAD due to PDE11A with early intervention

Carling and colleagues described in 2026, at a US adrenal surgical centre, a 13.5-year-old girl (bone age 13 years) referred for primary amenorrhoea, with thelarche at 10 years, growth stagnation (147 cm, 43.9 kg, body mass index 20.2 kg/m²) and mild fatigue; she had no moon facies, dorsocervical fat pad or striae, and BP was 110/70 mmHg [38]. Densitometry showed osteopenia, with a Z-score of −1.1 to −1.3 at the lumbar spine, femoral neck and total hip [38]. The family history spanned three generations: the mother had PPNAD diagnosed at 19 years, with severe CS and fragility fractures of the hip, and had undergone in 1998 open bilateral adrenalectomy by the posterior approach, with resection of the 12th ribs, 18 cm incisions and one month of recovery; the maternal grandmother had severe CS also treated with open bilateral adrenalectomy [38].

Biochemical assessment showed a paradoxical rise in cortisol on the overnight 8 mg DST (from 13.2 to 15.6 µg/dL), suppressed ACTH (7–8 pg/mL), normal UFC (43.7 µg/24 h; reference <45), slightly raised late-night salivary cortisol (0.09–0.12 µg/dL; reference <0.09) and a suppressed gonadotrophic axis (LH <0.02 mIU/mL, oestradiol <15 pg/mL), consistent with mild adrenal hypercortisolism [38]. Genetic testing identified the heterozygous PDE11A variant c.919C>T p.(Arg307Ter) (NM_016953.4; NC_000002.12:g.178014454G>A, confirmed in VariantValidator) [38, 82]. The first laboratory report had been negative, because the algorithm classified the variant as likely benign and did not report it; it was identified only after reanalysis targeted at the familial variant was requested [38]. Adrenal CT with a modified protocol showed normal-appearing glands, with little retroperitoneal fat as expected for age [38].

The team performed a right total adrenalectomy by posterior retroperitoneoscopy (18 minutes, without complications), which showed pigmented nodules of 2–5 mm; histology revealed adrenocortical hyperplasia with pigmented micronodules without atypia, consistent with PPNAD [38]. Three months later the left total adrenalectomy was performed, with discharge in less than 24 hours after each procedure; partial adrenalectomy preserving 30% was rejected because of the risk of recurrence and the severity of the familial disease [38]. The patient started hydrocortisone 5–5–2.5 mg every 8 h (8 mg/m²/day) and fludrocortisone 0.1 mg/day, without adrenal crises or withdrawal syndrome, and resumed linear growth and puberty, with LH and oestradiol at pubertal values [38]. Figure 1 of the article (consulted) shows the CT and the intraoperative findings (https://pmc.ncbi.nlm.nih.gov/articles/PMC12895349/figure/luaf329-F1/) and figure 2 (consulted) the macroscopy, histology at 40× and 100× and the comparison between the scars of daughter and mother (https://pmc.ncbi.nlm.nih.gov/articles/PMC12895349/figure/luaf329-F2/) [38].

The case illustrates four points about the class. First, a rare truncating PDE11A allele may behave as a Mendelian allele in a family, unlike the frequent missense variants, which are modulators [87, 88]. Second, the paradoxical response to dexamethasone identifies PPNAD when UFC is normal and CT shows no abnormalities [19]. Third, a negative report may result from bioinformatic filtering and should be reviewed when a familial variant is known. Fourth, cascade testing allowed the disease to be treated before severe bone complications. The decision to perform bilateral adrenalectomy in mild hypercortisolism with normal UFC is a choice of the centre, supported by the familial severity and the impact on growth and puberty; the guidelines indicate bilateral adrenalectomy as the definitive treatment of PPNAD, but do not define the biochemical threshold for operating on carriers with mild disease, and the hydrocortisone dose used (8 mg/m²/day) is lower than that proposed by the Endocrine Society for replacement after surgery (10–12 mg/m²/day) [2].

10.2 Complementary case: PBMAH with an ARMC5 variant of uncertain significance

O'Connor-Ramiro and colleagues described in 2026, in Pamplona (Spain), a 63-year-old man with ulcerative colitis, depression, hip osteoarthritis and hypertension, without typical signs of CS (body mass index 28.1 kg/m², BP 150/99 mmHg), with UFC of 154.8 µg/24 h (reference <100), ACTH <5 pg/mL, late-night plasma cortisol of 11.45 µg/dL and cortisol of 12 µg/dL (331 nmol/L) after 1 mg dexamethasone; MRI showed adrenals of 45×43×60 and 50×30×62 mm [108]. He had non-dipping hypertension, osteoporosis, dyslipidaemia and prediabetes; renin was suppressed, but hyperaldosteronism was excluded by the captopril test, and aberrant receptor tests (posture, meal, thyrotrophin-releasing hormone 200 µg, gonadotrophin-releasing hormone 100 µg) were negative [108]. The 9-gene panel (AIP, APC, ARMC5, CDKN1B, FH, GNAS, MC2R, MEN1, PRKACA) identified the heterozygous variant ARMC5 c.2525T>C p.(Phe842Ser), classified as VUS (PM2, PP4) and confirmed in VariantValidator as NM_001105247.2:c.2525T>C (NC_000016.10:g.31466606T>C) [82, 108]. He also had hyperprolactinaemia (81.11 ng/mL) with hypogonadotrophic hypogonadism and an 8×4 mm pituitary microadenoma, treated with cabergoline 0.5 mg twice weekly, with disappearance of the adenoma at 18 months [108].

With progression of hypercortisolism (UFC of 444.8 µg/24 h, >3 times the ULN), norcholesterol scintigraphy showed greater uptake on the right and the patient underwent right adrenalectomy, followed by adrenal insufficiency (basal cortisol 5.2 µg/dL; peak of 17 µg/dL on the ACTH test) treated with hydrocortisone for about 7 months; UFC was 24.8 µg/24 h after 5 months and 61.7 µg/24 h after 13 months, and antihypertensive drugs were stopped [108]. Figures 1 (pituitary MRI) and 2 (CT with enlarged adrenals and scintigraphy), consulted, are at https://pmc.ncbi.nlm.nih.gov/articles/PMC12770818/figure/luaf288-F1/ and https://pmc.ncbi.nlm.nih.gov/articles/PMC12770818/figure/luaf288-F2/ [108]. The case shows the option of unilateral adrenalectomy of the dominant gland in PBMAH and the need for surveillance for recurrence, which the authors estimate at 10–68%; the ARMC5 variant, being a VUS, does not support causality for either the PBMAH or the prolactinoma, and a segregation study was planned [5, 108].

11. Prognosis and Long-Term Follow-Up

11.1 Prognosis

CS increases mortality, particularly when hypercortisolism persists. In a comparison of 343 patients with 34,000 controls, the hazard ratio (HR) for death was 2.3 (95% CI 1.8–2.9); in 371 patients with CD it was 2.1 (1.5–2.8), with cardiovascular causes in 48.5% and infections in 18.2% of deaths; absence of remission at 2 years had an HR of 1.44 (1.00–2.17) [26]. The standardised mortality ratio (SMR) was 4.99 (2.15–9.83) in persistent disease versus 1.66 (0.34–4.85) after remission, and a meta-analysis of 14 studies with 3691 patients gave an overall SMR of 3.0 (2.3–3.9), 2.8 in CD and 3.3 in adrenal causes; cancer mortality at 10 years was double that of controls [26]. The Endocrine Society gives an SMR of 1.7–4.8 in active CS and an HR of 2.8–16 in persistence or recurrence, with excess cardiovascular, venous thrombotic and infectious deaths [2]. After bilateral adrenalectomy, 10-year mortality was 3% in CD, 10% in bilateral adrenal hyperplasia and 44% in ectopic secretion [2].

By entity, CNC has a mean life expectancy of ~50 years, determined by cardiac myxoma, psammomatous melanotic schwannoma and associated malignant tumours rather than by treated PPNAD [19]. In PPNAD and PRKACA copy gain, bilateral adrenalectomy cures the hypercortisolism, with a good long-term outcome [2, 42]. In PBMAH, bilateral surgery has no recurrence when complete, and unilateral surgery has recurrence in 29–55% depending on the series and the degree of hypercortisolism [5, 26]. In CD, TSS gives remission in ~80% of microadenomas and ~60% of macroadenomas, with recurrence in 5–35% [24]; in MEN1, immediate cure was 92% and 67% [13]. In Cushing of MAS, mortality was 20% in the NIH series, more likely with cardiac disease, and 44.4% of patients had cognitive or developmental impairment [23]. In ACC of the predisposition syndromes, prognosis depends on stage; in Paraná, tumours detected under surveillance were smaller and those not under surveillance more advanced [59].

The PNDS notes that some complications (metabolic syndrome, cardiovascular risk, bone and height impact, cognitive deficits, aesthetic impact and impact on quality of life) are not necessarily corrected by cure, and that fluctuating physical and cognitive asthenia, reduced stress tolerance, pain and muscle weakness are the complaints that weigh most on quality of life, with a barely visible disability that follow-up should recognise [22].

11.2 Surveillance

HU: Hounsfield units; DHEA-S: dehydroepiandrosterone sulphate; IGF-1: insulin-like growth factor 1.

The starting ages and intervals of surveillance for ARMC5 and KDM1A carriers are expert opinion and should be defined in prospective cohorts [5]. For asymptomatic PRKAR1A or PDE11A carriers with MACS, the sources consulted do not define when to operate; the São Paulo cohort documents that such carriers exist and the Carling family was operated on after an impact on growth and puberty [38, 83]. The PNDS justifies combining clinical and biochemical assessment because clinical signs of recurrence appear late, and late-night cortisol, serum or salivary, is one of the first parameters to change, before UFC [22].

12. Summary and Final Considerations

Cushing syndrome of genetic cause groups entities with a common outcome, endogenous hypercortisolism, and distinct mechanisms. Bilateral micronodular disease (isolated PPNAD or within Carney complex) results from increased cAMP–PKA signalling due to loss of PRKAR1A, copy gain of PRKACA or PRKACB, or loss of function of phosphodiesterases (PDE11A, PDE8B), and manifests in children and young adults with glands that sometimes appear normal and a paradoxical response to dexamethasone. Bilateral macronodular disease (PBMAH, now BMAD) is a disease of adults, frequently incidental, in which ARMC5 explains about one fifth of index cases and almost all familial cases, and KDM1A explains the food-dependent form mediated by the GIP receptor, identifiable by a morning/midnight cortisol ratio <0.65. Somatic forms (PRKACA p.Leu206Arg in adenomas, USP8 in corticotroph tumours) and post-zygotic forms (GNAS in MAS) have no familial implications, unlike the hereditary syndromes with corticotroph tumour (MEN1, MEN4, DICER1, Lynch) or adrenocortical carcinoma (Li-Fraumeni, with the Brazilian founder variant p.(Arg337His), BWS, MEN1).

Diagnosis follows three steps: confirm hypercortisolism with two concordant tests (1 mg DST, UFC, late-night salivary cortisol) after excluding exogenous glucocorticoids and pseudo-Cushing states; establish ACTH dependence and localise the lesion; and choose the genetic test by phenotype, bearing in mind that sequencing does not detect large PRKAR1A deletions or PRKACA copy gain, that the somatic second hit of PBMAH does not appear in blood and that the mosaicism of MAS requires affected tissue. Definitive treatment is surgical: bilateral adrenalectomy in PPNAD and severe MAS, unilateral adrenalectomy of the larger gland or bilateral adrenalectomy in PBMAH according to severity, TSS in CD. Steroidogenesis inhibitors (osilodrostat, metyrapone, ketoconazole, levoketoconazole), pasireotide, cabergoline and mifepristone control hypercortisolism before or instead of surgery, with doses and indications that differ between guidelines and labels and between the USA, the EU, Portugal and Brazil; none is authorised in pregnancy, and in children only ketoconazole (from 12 years, in the EU) and mitotane have a labelled dosage. Thromboprophylaxis, glucocorticoid replacement with education about adrenal insufficiency and treatment of comorbidities are part of the treatment.

Follow-up is lifelong: detection of recurrence after surgery, surveillance of the extra-adrenal manifestations of the underlying syndrome and surveillance of carriers identified by cascade testing. Gaps remain: the penetrance of ARMC5, KDM1A and PDE11A alleles has not been quantified, carrier surveillance intervals rest on expert opinion, there are no therapeutic trials directed at the genetic forms or at children, and relacorilant awaits a regulatory decision in the USA. In France, the 2022 PNDS organises the care pathway in adrenal reference and competence centres and differs from the international guidelines in some thresholds, doses and intervals (section 7.17) [22].

13. References

1. Nieman LK, Biller BM, Findling JW, Newell-Price J, Savage MO, Stewart PM, et al. The diagnosis of Cushing's syndrome: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2008;93(5):1526-40. doi:10.1210/jc.2008-0125. PMID: 18334580; PMC2386281.
2. Nieman LK, Biller BM, Findling JW, Murad MH, Newell-Price J, Savage MO, et al. Treatment of Cushing's Syndrome: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2015;100(8):2807-31. doi:10.1210/jc.2015-1818. PMID: 26222757; PMC4525003.
3. Orphanet. Rare disease with adrenal Cushing syndrome as a major feature. ORPHA:314749. https://www.orpha.net/en/disease/detail/314749
4. Mete O, Erickson LA, Juhlin CC, de Krijger RR, Sasano H, Volante M, et al. Overview of the 2022 WHO Classification of Adrenal Cortical Tumors. Endocr Pathol. 2022;33(1):155-196. doi:10.1007/s12022-022-09710-8. PMID: 35288842; PMC8920443.
5. Bertherat J, Bourdeau I, Bouys L, Chasseloup F, Kamenický P, Lacroix A. Clinical, Pathophysiologic, Genetic, and Therapeutic Progress in Primary Bilateral Macronodular Adrenal Hyperplasia. Endocr Rev. 2023;44(4):567-628. doi:10.1210/endrev/bnac034. PMID: 36548967.
6. GeneGuidance. PRKAR1A gene record [local curation database, with primary references and OMIM, ClinGen, GenCC and Orphadata data]. Accessed 26 Oct 2026.
7. GeneGuidance. PRKACA gene record [local curation database, with primary references and OMIM, ClinGen, GenCC and Orphadata data]. Accessed 26 Oct 2026.
8. GeneGuidance. PDE11A gene record [local curation database, with primary references and OMIM, ClinGen, GenCC and Orphadata data]. Accessed 26 Oct 2026.
9. GeneGuidance. PDE8B gene record [local curation database, with primary references and OMIM, ClinGen, GenCC and Orphadata data]. Accessed 26 Oct 2026.
10. GeneGuidance. ARMC5 gene record [local curation database, with primary references and OMIM, ClinGen, GenCC and Orphadata data]. Accessed 26 Oct 2026.
11. GeneGuidance. KDM1A gene record [local curation database, with primary references and OMIM, ClinGen, GenCC and Orphadata data]. Accessed 26 Oct 2026.
12. GeneGuidance. USP8 gene record [local curation database, with primary references and OMIM, ClinGen, GenCC and Orphadata data]. Accessed 26 Oct 2026.
13. Giusti F, Marini F, Brandi ML. Multiple Endocrine Neoplasia Type 1. 2005-08-31 [updated 2022-03-10]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1538/
14. Brock P, Kirschner L. Multiple Endocrine Neoplasia Type 4. 2023-09-21. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK594826/
15. Schultz KAP, Nelson AT, Kamihara J, Bauer AJ, Hatton J, Merideth MA, et al. DICER1-Related Tumor Predisposition. 2014-04-24 [updated 2026-03-25]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK196157/
16. Schneider K, Zelley K, Nichols KE, Levine AS, Garber J. Li-Fraumeni Syndrome. 1999-01-19 [updated 2024-09-05] [reviewed 2025-05-01]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1311/
17. Shuman C, Kalish JM, Weksberg R. Beckwith-Wiedemann Syndrome. 2000-03-03 [updated 2023-06-08] [reviewed 2023-09-21]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1394/
18. Szymczuk V, Florenzano P, de Castro LF, Collins MT, Boyce AM. Fibrous Dysplasia / McCune-Albright Syndrome. 2015-02-26 [updated 2024-02-08] [reviewed 2019-06-27]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK274564/
19. Stratakis CA. Carney Complex. 2003-02-05 [updated 2023-09-21]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1286/
20. Bouys L, Vaczlavik A, Cavalcante IP, Violon F, Jouinot A, Berthon A, et al. The mutational landscape of ARMC5 in Primary Bilateral Macronodular Adrenal Hyperplasia: an update. Orphanet J Rare Dis. 2025;20(1):51. doi:10.1186/s13023-025-03554-1. PMID: 39910635; PMC11796173.
21. Vaczlavik A, Bouys L, Violon F, Giannone G, Jouinot A, Armignacco R, et al. KDM1A inactivation causes hereditary food-dependent Cushing syndrome. Genet Med. 2022;24(2):374-383. doi:10.1016/j.gim.2021.09.018. PMID: 34906447.
22. Haute Autorité de Santé. Protocole National de Diagnostic et de Soins (PNDS): Syndrome de Cushing. Centre de référence des maladies rares de la surrénale (coordinated by Bertherat J, Hôpital Cochin, Paris), filière FIRENDO. Saint-Denis La Plaine: HAS; 2022 text, published 23 Mar 2023. Available from: https://www.has-sante.fr/jcms/p_3403769
23. Brown RJ, Kelly MH, Collins MT. Cushing syndrome in the McCune-Albright syndrome. J Clin Endocrinol Metab. 2010;95(4):1508-15. doi:10.1210/jc.2009-2321. PMID: 20157193; PMC2853983.
24. Fleseriu M, Auchus R, Bancos I, Ben-Shlomo A, Bertherat J, Biermasz NR, et al. Consensus on diagnosis and management of Cushing's disease: a guideline update. Lancet Diabetes Endocrinol. 2021;9(12):847-875. doi:10.1016/S2213-8587(21)00235-7. PMID: 34687601; PMC8743006.
25. Fassnacht M, Dekkers OM, Else T, Baudin E, Berruti A, de Krijger R, et al. European Society of Endocrinology Clinical Practice Guidelines on the management of adrenocortical carcinoma in adults, in collaboration with the European Network for the Study of Adrenal Tumors. Eur J Endocrinol. 2018;179(4):G1-G46. doi:10.1530/EJE-18-0608. PMID: 30299884.
26. Araujo-Castro M, Lamas C, Nowak E, Newell-Price J, Reincke M, Castinetti F. Update and Practical Recommendations for the Use of Medical Treatment of Cushing Syndrome. Endocr Rev. 2026;47(3):301-328. doi:10.1210/endrev/bnaf042. PMID: 41489578; PMC13167195.
27. Endo-ERN — European Reference Network on Rare Endocrine Conditions. https://endo-ern.eu/
28. Orphanet. Carney complex. ORPHA:1359. https://www.orpha.net/en/disease/detail/1359
29. OMIM® Online Mendelian Inheritance in Man. #160980 CARNEY COMPLEX, TYPE 1; CNC1. Johns Hopkins University; last edited 29/04/2019. https://omim.org/entry/160980. Accessed 28 October 2026.
30. OMIM® Online Mendelian Inheritance in Man. %605244 CARNEY COMPLEX, TYPE 2; CNC2. Johns Hopkins University; last edited 29/04/2019. https://omim.org/entry/605244. Accessed 28 October 2026.
31. OMIM® Online Mendelian Inheritance in Man. *188830 PROTEIN KINASE, cAMP-DEPENDENT, REGULATORY, TYPE I, ALPHA; PRKAR1A. Johns Hopkins University; last edited 29/02/2024. https://omim.org/entry/188830. Accessed 28 October 2026.
32. Orphanet. Isolated primary pigmented nodular adrenocortical disease. ORPHA:647772. https://www.orpha.net/en/disease/detail/647772
33. OMIM® Online Mendelian Inheritance in Man. #610489 PIGMENTED NODULAR ADRENOCORTICAL DISEASE, PRIMARY, 1; PPNAD1. Johns Hopkins University; last edited 29/02/2024. https://omim.org/entry/610489. Accessed 28 October 2026.
34. Sun J, Ding L, He L, Fu H, Li R, Feng J, et al. The clinical characteristics and pathogenic variants of primary pigmented nodular adrenocortical disease in 210 patients: a systematic review. Front Endocrinol (Lausanne) 2024;15:1356870. doi:10.3389/fendo.2024.1356870. PMID: 39006359.
35. Orphanet. Isolated micronodular adrenocortical disease. ORPHA:647782. https://www.orpha.net/en/disease/detail/647782
36. OMIM® Online Mendelian Inheritance in Man. #610475 PIGMENTED NODULAR ADRENOCORTICAL DISEASE, PRIMARY, 2; PPNAD2. Johns Hopkins University; last edited 16/05/2025. https://omim.org/entry/610475. Accessed 28 October 2026.
37. OMIM® Online Mendelian Inheritance in Man. #614190 PIGMENTED NODULAR ADRENOCORTICAL DISEASE, PRIMARY, 3; PPNAD3. Johns Hopkins University; last edited 29/04/2016. https://omim.org/entry/614190. Accessed 28 October 2026.
38. Carling T, LaRue M, Lenz AM, Kalik A, Faucz FR, Stratakis CA. Preventing Cushing Syndrome: Adrenalectomy in PDE11A-Positive Primary Pigmented Nodular Adrenocortical Disease. JCEM Case Rep. 2026;4(2):luaf329. doi:10.1210/jcemcr/luaf329. PMID: 41694449; PMC12895349.
39. OMIM® Online Mendelian Inheritance in Man. #615830 PIGMENTED NODULAR ADRENOCORTICAL DISEASE, PRIMARY, 4; PPNAD4. Johns Hopkins University; last edited 13/11/2020. https://omim.org/entry/615830. Accessed 28 October 2026.
40. Beuschlein F, Fassnacht M, Assié G, Calebiro D, Stratakis CA, Osswald A, et al. Constitutive activation of PKA catalytic subunit in adrenal Cushing's syndrome. N Engl J Med. 2014;370(11):1019-28. doi:10.1056/NEJMoa1310359. PMID: 24571724; PMC4727447.
41. Lodish MB, Yuan B, Levy I, Braunstein GD, Lyssikatos C, Salpea P, et al. Germline PRKACA amplification causes variable phenotypes that may depend on the extent of the genomic defect: molecular mechanisms and clinical presentations. Eur J Endocrinol. 2015;172(6):803-11. doi:10.1530/EJE-14-1154. PMID: 25924874; PMC4428149.
42. Carney JA, Lyssikatos C, Lodish MB, Stratakis CA. Germline PRKACA amplification leads to Cushing syndrome caused by 3 adrenocortical pathologic phenotypes. Hum Pathol. 2015;46(1):40-9. doi:10.1016/j.humpath.2014.09.005. PMID: 25449630; PMC6309372.
43. Goh G, Scholl UI, Healy JM, Choi M, Prasad ML, Nelson-Williams C, et al. Recurrent activating mutation in PRKACA in cortisol-producing adrenal tumors. Nat Genet. 2014;46(6):613-7. doi:10.1038/ng.2956. PMID: 24747643; PMC4074779.
44. Orphanet. Cushing syndrome due to bilateral macronodular adrenocortical disease. ORPHA:189427. https://www.orpha.net/en/disease/detail/189427
45. OMIM® Online Mendelian Inheritance in Man. #219080 ACTH-INDEPENDENT MACRONODULAR ADRENAL HYPERPLASIA 1; AIMAH1. Johns Hopkins University; last edited 15/07/2025. https://omim.org/entry/219080. Accessed 28 October 2026.
46. OMIM® Online Mendelian Inheritance in Man. #615954 ACTH-INDEPENDENT MACRONODULAR ADRENAL HYPERPLASIA 2; AIMAH2. Johns Hopkins University; last edited 28/06/2022. https://omim.org/entry/615954. Accessed 28 October 2026.
47. OMIM® Online Mendelian Inheritance in Man. #620990 ACTH-INDEPENDENT MACRONODULAR ADRENAL HYPERPLASIA 3; AIMAH3. Johns Hopkins University; last edited 22/05/2025. https://omim.org/entry/620990. Accessed 28 October 2026.
48. Bouys L, Vaduva P, Jouinot A, Violon F, Vaczlavik A, Barat M, et al. KDM1A genetic alterations, a rare cause of primary bilateral macronodular adrenal hyperplasia, strongly associated with food-dependent Cushing's syndrome: results of its systematic germline screening in 301 index cases and genotype/phenotype correlation. Eur J Endocrinol. 2025;192(2):119-127. doi:10.1093/ejendo/lvaf016. PMID: 39921449.
49. GeneGuidance. GNAS gene record [local curation database, with primary references and OMIM, ClinGen, GenCC and Orphadata data]. Accessed 26 Oct 2026.
50. OMIM® Online Mendelian Inheritance in Man. #131100 MULTIPLE ENDOCRINE NEOPLASIA, TYPE I; MEN1. Johns Hopkins University; last edited 26/08/2026. https://omim.org/entry/131100. Accessed 28 October 2026.
51. GeneGuidance. MEN1 gene record [local curation database, with primary references and OMIM, ClinGen, GenCC and Orphadata data]. Accessed 26 Oct 2026.
52. OMIM® Online Mendelian Inheritance in Man. #610755 MULTIPLE ENDOCRINE NEOPLASIA, TYPE IV; MEN4. Johns Hopkins University; last edited 02/08/2017. https://omim.org/entry/610755. Accessed 28 October 2026.
53. Chasseloup F, Pankratz N, Lane J, Faucz FR, Keil MF, Chittiboina P, et al. Germline CDKN1B Loss-of-Function Variants Cause Pediatric Cushing's Disease With or Without an MEN4 Phenotype. J Clin Endocrinol Metab. 2020;105(6):1983-2005. doi:10.1210/clinem/dgaa160. PMID: 32232325.
54. Orphanet. Cushing disease. ORPHA:96253. https://www.orpha.net/en/disease/detail/96253
55. OMIM® Online Mendelian Inheritance in Man. #219090 PITUITARY ADENOMA 4, ACTH-SECRETING; PITA4. Johns Hopkins University; last edited 27/09/2017. https://omim.org/entry/219090. Accessed 28 October 2026.
56. Perez-Rivas LG, Theodoropoulou M, Ferraù F, Nusser C, Kawaguchi K, Stratakis CA, et al. The Gene of the Ubiquitin-Specific Protease 8 Is Frequently Mutated in Adenomas Causing Cushing's Disease. J Clin Endocrinol Metab. 2015;100(7):E997-1004. doi:10.1210/jc.2015-1453. PMID: 25942478; PMC4490309.
57. Orphanet. McCune-Albright syndrome. ORPHA:562. https://www.orpha.net/en/disease/detail/562
58. OMIM® Online Mendelian Inheritance in Man. #174800 MCCUNE-ALBRIGHT SYNDROME; MAS. Johns Hopkins University; last edited 21/09/2022. https://omim.org/entry/174800. Accessed 28 October 2026.
59. Custódio G, Parise GA, Kiesel Filho N, Komechen H, Sabbaga CC, Rosati R, et al. Impact of neonatal screening and surveillance for the TP53 R337H mutation on early detection of childhood adrenocortical tumors. J Clin Oncol. 2013;31(20):2619-26. doi:10.1200/JCO.2012.46.3711. PMID: 23733769; PMC3808236.
60. Friedman JM. Neurofibromatosis 1. 1998-10-02 [updated 2022-04-21] [reviewed 2025-04-03]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1109/
61. Bano G, Mir F, Beharry N, Wilson P, Hodgson S, Schey S. A Novel Medical Treatment of Cushing's Due to Ectopic ACTH in a Patient With Neurofibromatosis Type 1. Int J Endocrinol Metab. 2013;11(1):52-6. doi:10.5812/ijem.6898. PMID: 23853621; PMC3693655.
62. Kobus K, Hartl D, Ott CE, Osswald M, Huebner A, von der Hagen M, et al. Double NF1 inactivation affects adrenocortical function in NF1Prx1 mice and a human patient. PLoS One. 2015;10(3):e0119030. doi:10.1371/journal.pone.0119030. PMID: 25775093; PMC4361563.
63. Jones KL, Jones MC, del Campo M. McCune-Albright syndrome. In: Smith's Recognizable Patterns of Human Malformation. 8th ed. Philadelphia: Elsevier; 2022. p. 720–723.
64. Carney JA, Gordon H, Carpenter PC, Shenoy BV, Go VL. The complex of myxomas, spotty pigmentation, and endocrine overactivity. Medicine (Baltimore). 1985;64(4):270-83. doi:10.1097/00005792-198507000-00007. PMID: 4010501.
65. Lacroix A, Bolté E, Tremblay J, Dupré J, Poitras P, Fournier H, et al. Gastric inhibitory polypeptide-dependent cortisol hypersecretion--a new cause of Cushing's syndrome. N Engl J Med. 1992;327(14):974-80. doi:10.1056/NEJM199210013271402. PMID: 1325608.
66. Reznik Y, Allali-Zerah V, Chayvialle JA, Leroyer R, Leymarie P, Travert G, et al. Food-dependent Cushing's syndrome mediated by aberrant adrenal sensitivity to gastric inhibitory polypeptide. N Engl J Med. 1992;327(14):981-6. doi:10.1056/NEJM199210013271403. PMID: 1325609.
67. Weinstein LS, Shenker A, Gejman PV, Merino MJ, Friedman E, Spiegel AM. Activating mutations of the stimulatory G protein in the McCune-Albright syndrome. N Engl J Med. 1991;325(24):1688-95. doi:10.1056/NEJM199112123252403. PMID: 1944469.
68. Kirschner LS, Carney JA, Pack SD, Taymans SE, Giatzakis C, Cho YS, et al. Mutations of the gene encoding the protein kinase A type I-alpha regulatory subunit in patients with the Carney complex. Nat Genet. 2000;26(1):89-92. doi:10.1038/79238. PMID: 10973256.
69. Kirschner LS, Sandrini F, Monbo J, Lin JP, Carney JA, Stratakis CA. Genetic heterogeneity and spectrum of mutations of the PRKAR1A gene in patients with the carney complex. Hum Mol Genet. 2000;9(20):3037-46. doi:10.1093/hmg/9.20.3037. PMID: 11115848.
70. Horvath A, Boikos S, Giatzakis C, Robinson-White A, Groussin L, Griffin KJ, et al. A genome-wide scan identifies mutations in the gene encoding phosphodiesterase 11A4 (PDE11A) in individuals with adrenocortical hyperplasia. Nat Genet. 2006;38(7):794-800. doi:10.1038/ng1809. PMID: 16767104.
71. Horvath A, Mericq V, Stratakis CA. Mutation in PDE8B, a cyclic AMP-specific phosphodiesterase in adrenal hyperplasia. N Engl J Med. 2008;358(7):750-2. doi:10.1056/NEJMc0706182. PMID: 18272904.
72. Assié G, Libé R, Espiard S, Rizk-Rabin M, Guimier A, Luscap W, et al. ARMC5 mutations in macronodular adrenal hyperplasia with Cushing's syndrome. N Engl J Med. 2013;369(22):2105-14. doi:10.1056/NEJMoa1304603. PMID: 24283224; PMC4727443.
73. Cao Y, He M, Gao Z, Peng Y, Li Y, Li L, et al. Activating hotspot L205R mutation in PRKACA and adrenal Cushing's syndrome. Science. 2014;344(6186):913-7. doi:10.1126/science.1249480. PMID: 24700472.
74. Forlino A, Vetro A, Garavelli L, Ciccone R, London E, Stratakis CA, et al. PRKACB and Carney complex. N Engl J Med. 2014;370(11):1065-7. doi:10.1056/NEJMc1309730. PMID: 24571725.
75. Reincke M, Sbiera S, Hayakawa A, Theodoropoulou M, Osswald A, Beuschlein F, et al. Mutations in the deubiquitinase gene USP8 cause Cushing's disease. Nat Genet. 2015;47(1):31-8. doi:10.1038/ng.3166. PMID: 25485838.
76. Chasseloup F, Bourdeau I, Tabarin A, Regazzo D, Dumontet C, Ladurelle N, et al. Loss of KDM1A in GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome: a multicentre, retrospective, cohort study. Lancet Diabetes Endocrinol. 2021;9(12):813-824. doi:10.1016/S2213-8587(21)00236-9. PMID: 34655521.
77. de Kock L, Sabbaghian N, Plourde F, Srivastava A, Weber E, Bouron-Dal Soglio D, et al. Pituitary blastoma: a pathognomonic feature of germ-line DICER1 mutations. Acta Neuropathol. 2014;128(1):111-22. doi:10.1007/s00401-014-1285-z. PMID: 24839956; PMC4129448.
78. Firth HV, Hurst JA. Patterns of cancer. In: Oxford Desk Reference: Clinical Genetics and Genomics. 2nd ed. Oxford: Oxford University Press; 2017. p. 846–851.
79. Fassnacht M, Tsagarakis S, Terzolo M, Tabarin A, Sahdev A, Newell-Price J, et al. European Society of Endocrinology clinical practice guidelines on the management of adrenal incidentalomas, in collaboration with the European Network for the Study of Adrenal Tumors. Eur J Endocrinol. 2023;189(1):G1-G42. doi:10.1093/ejendo/lvad066. PMID: 37318239.
80. Carney JA, Young WF, Stratakis CA. Primary bimorphic adrenocortical disease: cause of hypercortisolism in McCune-Albright syndrome. Am J Surg Pathol. 2011;35(9):1311-26. doi:10.1097/PAS.0b013e31821ec4ce. PMID: 21836496; PMC4140081.
81. Salpea P, Horvath A, London E, Faucz FR, Vetro A, Levy I, et al. Deletions of the PRKAR1A locus at 17q24.2-q24.3 in Carney complex: genotype-phenotype correlations and implications for genetic testing. J Clin Endocrinol Metab. 2014;99(1):E183-8. doi:10.1210/jc.2013-3159. PMID: 24170103; PMC3879675.
82. Freeman PJ, Hart RK, Gretton LJ, Brookes AJ, Dalgleish R. VariantValidator: Accurate validation, mapping, and formatting of sequence variation descriptions. Hum Mutat 2018;39(1):61-68. doi:10.1002/humu.23348. PMID: 28967166. https://variantvalidator.org/ (accessed 2026-10-26).
83. Kuhn AW, Lerario AM, Charchar HL, Mariani BMP, Vaduva P, Nishi MY, et al. Integrated clinical-genetic-pathological analysis expands the phenotypic and molecular spectrum of PPNAD across carney complex and isolated forms. Eur J Endocrinol. 2026;195(2):217-228. doi:10.1093/ejendo/lvag137. PMID: 42543523.
84. Landrum MJ, Lee JM, Benson M, Brown GR, Chao C, Chitipiralla S, et al. ClinVar: improving access to variant interpretations and supporting evidence. Nucleic Acids Res. 2018;46(D1):D1062-D1067. doi:10.1093/nar/gkx1153. PMID: 29165669. Database: https://www.ncbi.nlm.nih.gov/clinvar/ (accessed 2026-10-28).
85. Korbonits M, Hernández-Ramírez LC. AIP Familial Isolated Pituitary Adenomas. 2012-06-21 [updated 2025-01-16] [reviewed 2025-11-20]. In: Adam MP, Feldman J, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2026. Available from: https://www.ncbi.nlm.nih.gov/books/NBK97965/
86. OMIM® Online Mendelian Inheritance in Man. #619143 CARDIOACROFACIAL DYSPLASIA 2; CAFD2. Johns Hopkins University; last edited 22/09/2021. https://omim.org/entry/619143. Accessed 28 October 2026.
87. Libé R, Horvath A, Vezzosi D, Fratticci A, Coste J, Perlemoine K, et al. Frequent phosphodiesterase 11A gene (PDE11A) defects in patients with Carney complex (CNC) caused by PRKAR1A mutations: PDE11A may contribute to adrenal and testicular tumors in CNC as a modifier of the phenotype. J Clin Endocrinol Metab. 2011;96(1):E208-14. doi:10.1210/jc.2010-1704. PMID: 21047926; PMC3038483.
88. Vaduva P, Bouys L, Jouinot A, Espiard S, Chansavang A, Berthon A, et al. PDE11A Is a Phenotype Modulator of Primary Bilateral Macronodular Adrenal Hyperplasia: Results of a 334-Patient Series. J Clin Endocrinol Metab. 2025;110(9):e2946-e2955. doi:10.1210/clinem/dgae918. PMID: 39774659; PMC12641522.
89. OMIM® Online Mendelian Inheritance in Man. #609161 STRIATAL DEGENERATION, AUTOSOMAL DOMINANT 1; ADSD1. Johns Hopkins University; last edited 07/06/2016. https://omim.org/entry/609161. Accessed 28 October 2026.
90. Bouys L, Vaczlavik A, Jouinot A, Vaduva P, Espiard S, Assié G, et al. Identification of predictive criteria for pathogenic variants of primary bilateral macronodular adrenal hyperplasia (PBMAH) gene ARMC5 in 352 unselected patients. Eur J Endocrinol. 2022;187(1):123-134. doi:10.1530/EJE-21-1032. PMID: 35521700.
91. Vena W, Morelli V, Carrabba M, Elli F, Fabio G, Muller I, et al. Case Report: A Novel ARMC5 Germline Mutation in a Patient with Primary Bilateral Macronodular Adrenal Hyperplasia and Hypogammaglobulinemia. Front Genet. 2022;13:834067. doi:10.3389/fgene.2022.834067. PMID: 35368666; PMCID: PMC8965228.
92. OMIM® Online Mendelian Inheritance in Man. #616728 CLEFT PALATE, PSYCHOMOTOR RETARDATION, AND DISTINCTIVE FACIAL FEATURES; CPRF. Johns Hopkins University; last edited 28/11/2022. https://omim.org/entry/616728. Accessed 28 October 2026.
93. Koukoula C, Kyriakopoulos G, Tsagarakis S, Vassiliadi DA. Primary Bilateral Macronodular Adrenal Hyperplasia. Endocrinol Metab Clin North Am. 2026;55(2):285-298. doi:10.1016/j.ecl.2026.01.005. PMID: 42067271.
94. Gatta-Cherifi B, Chabre O, Murat A, Niccoli P, Cardot-Bauters C, Rohmer V, et al. Adrenal involvement in MEN1. Analysis of 715 cases from the Groupe d'etude des Tumeurs Endocrines database. Eur J Endocrinol. 2012;166(2):269-79. doi:10.1530/EJE-11-0679. PMID: 22084155.
95. Langer P, Cupisti K, Bartsch DK, Nies C, Goretzki PE, Rothmund M, et al. Adrenal involvement in multiple endocrine neoplasia type 1. World J Surg. 2002;26(8):891-6. doi:10.1007/s00268-002-6492-4. PMID: 12016472.
96. Firth HV, Hurst JA. Multiple endocrine neoplasia (MEN). In: Oxford Desk Reference: Clinical Genetics and Genomics. 2nd ed. Oxford: Oxford University Press; 2017. p. 592–594.
97. Cohen M, Persky R, Stegemann R, Hernández-Ramírez LC, Zeltser D, Lodish MB, et al. Germline USP8 Mutation Associated With Pediatric Cushing Disease and Other Clinical Features: A New Syndrome. J Clin Endocrinol Metab. 2019;104(10):4676-4682. doi:10.1210/jc.2019-00697. PMID: 31162547; PMC6736211.
98. Sakamoto M, Kurosawa K, Tanoue K, Iwama K, Ishida F, Watanabe Y, et al. A heterozygous germline deletion within USP8 causes severe neurodevelopmental delay with multiorgan abnormalities. J Hum Genet. 2024;69(2):85-90. doi:10.1038/s10038-023-01209-2. PMID: 38030753.
99. Bengtsson D, Joost P, Aravidis C, Askmalm Stenmark M, Backman AS, Melin B, et al. Corticotroph Pituitary Carcinoma in a Patient With Lynch Syndrome (LS) and Pituitary Tumors in a Nationwide LS Cohort. J Clin Endocrinol Metab. 2017;102(11):3928-3932. doi:10.1210/jc.2017-01401. PMID: 28938458.
100. Zhang Q, Peng C, Song J, Zhang Y, Chen J, Song Z, et al. Germline Mutations in CDH23, Encoding Cadherin-Related 23, Are Associated with Both Familial and Sporadic Pituitary Adenomas. Am J Hum Genet. 2017;100(5):817-823. doi:10.1016/j.ajhg.2017.03.011. PMID: 28413019; PMC5420349.
101. OMIM® Online Mendelian Inheritance in Man. #617540 PITUITARY ADENOMA 5, MULTIPLE TYPES; PITA5. Johns Hopkins University; last edited 12/12/2025. https://omim.org/entry/617540. Accessed 28 October 2026.
102. Hannah-Shmouni F, Stratakis CA. An update on the genetics of benign pituitary adenomas in children and adolescents. Curr Opin Endocr Metab Res. 2018;1:19-24. doi:10.1016/j.coemr.2018.04.002. PMID: 30555957; PMC6289528.
103. Figueiredo BC, Sandrini R, Zambetti GP, Pereira RM, Cheng C, Liu W, et al. Penetrance of adrenocortical tumours associated with the germline TP53 R337H mutation. J Med Genet. 2006;43(1):91-6. doi:10.1136/jmg.2004.030551. PMID: 16033918; PMC2564508.
104. Pinto EM, Billerbeck AE, Villares MC, Domenice S, Mendonça BB, Latronico AC. Founder effect for the highly prevalent R337H mutation of tumor suppressor p53 in Brazilian patients with adrenocortical tumors. Arq Bras Endocrinol Metabol. 2004;48(5):647-50. doi:10.1590/s0004-27302004000500009. PMID: 15761534.
105. OMIM® Online Mendelian Inheritance in Man. #619142 CARDIOACROFACIAL DYSPLASIA 1; CAFD1. Johns Hopkins University; last edited 29/12/2020. https://omim.org/entry/619142. Accessed 28 October 2026.
106. GeneGuidance. CDKN1B gene record [local curation database, with primary references and OMIM, ClinGen, GenCC and Orphadata data]. Accessed 26 Oct 2026.
107. Nowak E, Zhang Q, Zhang S, Zhao Y, Ye H, Machado MC, et al. Cycle characterisation and clinical complications in patients with cyclic Cushing's syndrome: insights from an international retrospective cohort study. Lancet Diabetes Endocrinol. 2025;13(12):1030-1040. doi:10.1016/S2213-8587(25)00249-9. PMID: 41235993.
108. O'Connor-Ramiro L, Fernández PJ, Maroto J, Patiño-García A, Escalada J, Perdomo CM. Primary Bilateral Macronodular Adrenal Hyperplasia Associated With ARMC5 Variant and Pituitary Microadenoma. JCEM Case Rep. 2026;4(1):luaf288. doi:10.1210/jcemcr/luaf288. PMID: 41503047; PMC12770818.
109. Hamajima T, Maruwaka K, Homma K, Matsuo K, Fujieda K, Hasegawa T. Unilateral adrenalectomy can be an alternative therapy for infantile onset Cushing' s syndrome caused by ACTH-independent macronodular adrenal hyperplasia with McCune-Albright syndrome. Endocr J. 2010;57(9):819-24. doi:10.1507/endocrj.k10e-003. PMID: 20543510.
110. Mateus C, Palangié A, Franck N, Groussin L, Bertagna X, Avril MF, et al. Heterogeneity of skin manifestations in patients with Carney complex. J Am Acad Dermatol. 2008;59(5):801-10. doi:10.1016/j.jaad.2008.07.032. PMID: 18804312.
111. Firth HV, Hurst JA. Hemihypertrophy and limb asymmetry. In: Oxford Desk Reference: Clinical Genetics and Genomics. 2nd ed. Oxford: Oxford University Press; 2017. p. 164–167.
112. Jones KL, Jones MC, del Campo M. Hecht syndrome (trismus pseudocamptodactyly). In: Smith's Recognizable Patterns of Human Malformation. 8th ed. Philadelphia: Elsevier; 2022. p. 312–313.
113. Orphanet. Familial atrial myxoma. ORPHA:615. https://www.orpha.net/en/disease/detail/615
114. Jones KL, Jones MC, del Campo M. Acrodysostosis. In: Smith's Recognizable Patterns of Human Malformation. 8th ed. Philadelphia: Elsevier; 2022. p. 626–627.
115. Bouys L, Chiodini I, Arlt W, Reincke M, Bertherat J. Update on primary bilateral macronodular adrenal hyperplasia (PBMAH). Endocrine. 2021;71(3):595-603. doi:10.1007/s12020-021-02645-w. PMID: 33587256.
116. Recordati Rare Diseases. ISTURISA (osilodrostat) tablets, for oral use. Prescribing information. NDA 212801. Revised 2025-11. DailyMed/openFDA set id f3a5ec24-63c3-4d83-b1c0-6c550fbe7ae2. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=f3a5ec24-63c3-4d83-b1c0-6c550fbe7ae2
117. European Medicines Agency. Isturisa (osilodrostat) — EPAR, product information. EC authorisation 2020-01-09. https://www.ema.europa.eu/en/medicines/human/EPAR/isturisa
118. INFARMED. Metopirone 250 mg cápsulas moles — Resumo das Características do Medicamento (Esteve RD France SAS; text revised 11/2024). Infomed. https://extranet.infarmed.pt/INFOMED-fo/
119. HRA Pharma Rare Diseases. METOPIRONE (metyrapone) capsules. Prescribing information. NDA 012911. Revised 2026-01. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3a27d0ef-83a7-4e1c-9430-46a3326ee8d8
120. European Medicines Agency. Ketoconazole Esteve (previously Ketoconazole HRA) — EPAR, product information. EC authorisation 2014-11-18. https://www.ema.europa.eu/en/medicines/human/EPAR/ketoconazole-esteve
121. Xeris Pharmaceuticals. RECORLEV (levoketoconazole) tablets. Prescribing information. NDA 214133. Revised 2026-03. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d4c5fead-bc4a-fb02-e053-2a95a90ae4fc
122. Recordati Rare Diseases. SIGNIFOR (pasireotide) injection, NDA 200677 (revised 2026-02) and SIGNIFOR LAR (pasireotide) for injectable suspension, NDA 203255 (revised 2024-07). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a09a25fc-a5a3-0c82-e053-2995a90a5d74 ; https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a0aad470-3f38-af97-e053-2995a90a383a
123. European Medicines Agency. Signifor (pasireotide) — EPAR, product information. EC authorisation 2012-04-24. https://www.ema.europa.eu/en/medicines/human/EPAR/signifor
124. Corcept Therapeutics. KORLYM (mifepristone) 300 mg tablets. Prescribing information. NDA 202107. Revised 2025-09. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=542f3fae-8bc8-4f00-9228-e4b66c9ad6a9
125. Esteve Pharmaceuticals. LYSODREN (mitotane) tablets. Prescribing information. NDA 016885. Revised 2026-03. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4046a224-8832-daa2-e063-6294a90a11d7
126. European Medicines Agency. Lysodren (mitotane) — EPAR, product information. EC authorisation 2004-04-28. https://www.ema.europa.eu/en/medicines/human/EPAR/lysodren
127. Agência Nacional de Vigilância Sanitária (ANVISA). Open data — registered medicines (DADOS_ABERTOS_MEDICAMENTOS.csv). https://dados.anvisa.gov.br/dados/DADOS_ABERTOS_MEDICAMENTOS.csv
128. Novartis Pharmaceuticals Corporation. SANDOSTATIN (octreotide acetate) injection. Prescribing information. NDA 019667. Revised 2026-07-22. openFDA set id 4e2c9856-1836-49f0-9472-4dbeeb408f39. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4e2c9856-1836-49f0-9472-4dbeeb408f39
129. Isand K, Arima H, Bertherat J, Dekkers OM, Feelders RA, Fleseriu M, et al. Delphi panel consensus on recommendations for thromboprophylaxis of venous thromboembolism in endogenous Cushing's syndrome: a position statement. Eur J Endocrinol. 2025;192(3):R17-R27. doi:10.1093/ejendo/lvaf017. PMID: 39973025.
130. American Health Packaging. Fludrocortisone acetate tablets, 0.1 mg. Prescribing information (ANDA040431). Revised 2025-05-19. openFDA set id 001e72ea-2c9e-468c-90cc-6c347234e2a9. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=001e72ea-2c9e-468c-90cc-6c347234e2a9
131. U.S. Food and Drug Administration. Drugs@FDA: NDA 212801 ISTURISA — approval history (ORIG-1 2020-03-06; SUPPL-3 new indication 2025-04-15; SUPPL-4 new dosing regimen 2025-07-03). https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=212801
132. INFARMED. Infomed — medicine search (Signifor, Isturisa, osilodrostat, ketoconazole, mitotane). https://extranet.infarmed.pt/INFOMED-fo/
133. European Medicines Agency. Download medicine data: medicines for human use (Medicines output). https://www.ema.europa.eu/en/medicines/download-medicine-data
134. Corcept Therapeutics. Corcept receives Complete Response Letter for relacorilant as a treatment for patients with hypercortisolism [press release, Form 8-K Exhibit 99.1]. 2025 Dec 31. https://www.sec.gov/Archives/edgar/data/1088856/000119312525338184/d50993dex991.htm
135. Corcept Therapeutics. Quarterly report (Form 10-Q) for the period ended June 30, 2026. Filed 2026 Jul 29. https://www.sec.gov/Archives/edgar/data/1088856/000162828026050613/cort-20260630.htm
136. Nieman LK, Boscaro M, Scaroni C, Deutschbein T, Mezôsi E, Driessens N, et al. Prospective study of metyrapone in endogenous Cushing's syndrome (PROMPT). Eur J Endocrinol. 2025;193(3):391-402. doi:10.1093/ejendo/lvaf181. PMID: 40966724; PMC13187941.
137. ClinicalTrials.gov. NCT03697109 — GRACE: relacorilant in endogenous Cushing syndrome (phase 3). https://clinicaltrials.gov/study/NCT03697109
138. ClinicalTrials.gov. NCT04308590 — GRADIENT: relacorilant in cortisol-secreting adrenal adenomas or hyperplasia (phase 3). https://clinicaltrials.gov/study/NCT04308590
139. ClinicalTrials.gov. NCT03708900 — osilodrostat PK/PD and tolerability in pediatric Cushing's syndrome (phase 2). https://clinicaltrials.gov/study/NCT03708900
140. Maria F, de Ven Kees V, Maria R, Simone A, Shipra A, Perazollo AA, et al. International Delphi-based consensus: therapeutic approaches for pediatric adrenocortical carcinoma. Eur J Endocrinol. 2026;195(1):R23-R47. doi:10.1093/ejendo/lvag101. PMID: 42324800.
141. Charoenngam N, Wannachalee T. Global prevalence of genetic carriers for ARMC5- and KDM1A-associated primary bilateral macronodular adrenal hyperplasia: insights from a large multiethnic genomic database. J Endocrinol Invest. 2026;49(9):2291-2303. doi:10.1007/s40618-026-02920-5. PMID: 42171680; PMC13498619.
142. ClinicalTrials.gov. NCT05436639 — SPI-62 for hypercortisolism related to a benign adrenal tumor (phase 2). https://clinicaltrials.gov/study/NCT05436639
143. Bertherat J, Horvath A, Groussin L, Grabar S, Boikos S, Cazabat L, et al. Mutations in regulatory subunit type 1A of cyclic adenosine 5'-monophosphate-dependent protein kinase (PRKAR1A): phenotype analysis in 353 patients and 80 different genotypes. J Clin Endocrinol Metab. 2009;94(6):2085-91. doi:10.1210/jc.2008-2333. PMID: 19293268.
144. Valério M, Croca GP, Simões J, Ferreira P, Costa DC, Knoblich M, et al. Case report: ACTH-independent Cushing's syndrome caused by isolated micronodular adrenal disease in a 23-month-old girl. Front Endocrinol (Lausanne). 2026;17:1863025. doi:10.3389/fendo.2026.1863025
145. Cushing's Support & Research Foundation (CSRF). https://csrf.net/
146. Carney Complex Community. https://carneycomplex.org/
147. The Pituitary Foundation. https://www.pituitary.org.uk/