Identification of predictive criteria for pathogenic variants of primary bilateral macronodular adrenal hyperplasia (PBMAH) gene ARMC5 in 352 unselected patients

Long-term cardiometabolic outcomes of primary bilateral macronodular adrenal hyperplasia

PURPOSE

This study investigated long-term alterations in cardiometabolic comorbidities among patients with primary bilateral macronodular adrenal hyperplasia (PBMAH) who received surgical or conservative treatments.

METHODS

A single-center, retrospective study analyzed 132 patients with PBMAH, divided into a surgery group (n = 68) and a control group (n = 64) based on treatment modalities. The main outcomes included changes in blood pressure (BP), blood glucose, lipids, and body weight.

RESULTS

Among the 132 patients, hypertension, abnormal glucose metabolism, dyslipidemia, and overweight/obesity were prevalent in over 50% of cases. The surgery group demonstrated significantly greater improvements in BP, blood glucose, and weight control compared with the control group. Adrenalectomy was associated with enhanced BP control, blood glucose control, and at least one cardiometabolic risk factor control. In a group of 95 patients with mild autonomous cortisol secretion, the surgery group also exhibited higher rates of improvement in BP and blood glucose than the control group. Adrenalectomy was associated with improved BP, blood glucose, and at least one cardiometabolic risk factor.

CONCLUSION

Our study observed that most patients with PBMAH exhibited at least one cardiometabolic risk factor. Adrenalectomy was associated with improved BP and blood glucose for patients with PBMAH, including those with mild autonomous cortisol secretion.

ARMC5 mutations in primary bilateral macronodular adrenal hyperplasia: a family case report

BACKGROUND

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a rare cause of overt Cushing's syndrome (CS), which usually manifests as bilateral macronodular adrenal nodules and varying levels of cortisol secretion. Previous studies have shown that ARMC5 play a huge role in the occurrence of PBMAH, which may be inherited to family members and lead to more severe clinical symptoms. ARMC5 variants may be associated with meningiomas, which is also illustrated by our report.

CASE PRESENTATION

This is a 41-year-old male patient with high blood pressure for 10 years and multiple adrenal nodules on both sides. In addition, the patient also suffered from pituitary microadenoma and meningioma. According to the patient's clinical manifestations, laboratory tests, imaging examinations, and the results of whole exon gene testing, we diagnosed the patient with PBMAH. The patient underwent a posterior laparoscopic nephrectomy of the left adrenal gland. Pathology reported a left macronodular adrenal hyperplasia, multifocal, 2 cm to 3 cm in diameter. Molecular analysis of DNA extracted from the patient's peripheral blood revealed an ARMC5 heterozygous mutation, which was classified as likely pathogenic.

CONCLUSION

Screening of family members of PBMAH patients with ARMC5 germline mutations and active monitoring of family members carrying ARMC5 variants are recommended.

Prevalence and main characteristics of primary aldosteronism in bilateral macronodular adrenal disease: a systematic review of the literature

CONTEXT

Bilateral macronodular adrenal disease (BMAD) typically presents with bilateral benign adrenocortical macronodules and variable cortisol excess. Anecdotal evidence suggests oversecretion of other adrenal steroids, including mineralocorticoids.

HYPOTHESIS

We hypothesized that primary aldosteronism (PA) can occur in BMAD, resulting in a distinct, more severe phenotype compared to BMAD with isolated cortisol hypersecretion or unilateral PA (uPA).

OBJECTIVE

To assess the prevalence and characteristics of PA in BMAD.

METHODS

We systematically reviewed case reports and series of BMAD patients with PA, following PRISMA guidelines. BMAD was defined by bilateral adrenal nodules ≥10 mm. PA diagnosis followed US or Japanese Endocrine Society guidelines. We compared these findings with 2 cohorts from LMU Hospital Munich: BMAD with isolated cortisol hypersecretion and uPA.

RESULTS

From 1018 articles, 18 representing 68 cases were included. Of these, 66 had BMAD with PA and 2 had BMAD with aldosterone precursor excess. The PA proportion in published BMAD series ranged from 2% to 43%. BMAD patients with PA were predominantly male (75%) and younger (median 51.5 years) than those with isolated cortisol hypersecretion (median 60.5 years, P < .01). Their median blood pressure was higher (170/100 mm Hg) compared to those with isolated cortisol hypersecretion (138/80 mm Hg) or uPA (153/94 mm Hg, P < .01). Treatment was only described in 28 cases, with 93% undergoing adrenalectomy. Clinical outcome was similar across groups post-treatment.

CONCLUSION

This review highlights the need for increased screening for PA in younger, hypertensive BMAD patients. Larger multicenter studies are needed to determine the association between these conditions, cardiovascular risk, and optimal treatment.

The mutational landscape of ARMC5 in Primary Bilateral Macronodular Adrenal Hyperplasia: an update

BACKGROUND

Primary Bilateral Macronodular Adrenal Hyperplasia (PBMAH) is a rare cause of Cushing's syndrome due to bilateral adrenocortical macronodules. Germline inactivating variants of the tumor suppressor gene ARMC5 are responsible for 20-25% of apparently sporadic PBMAH cases and 80% of familial presentations. ARMC5 screening is now routinely performed for PBMAH patients and families. Based on literature review and own observation, this study aims to give an overview of both published and unpublished ARMC5 genetic alterations and to compile the available evidence to discriminate pathogenic from benign variants.

RESULTS

146 different germline variants (110 previously published and 36 novel) are identified, including 46% missense substitutions, 45% truncating variants, 3% affecting splice sites, 4% in-frame variants and 2% large deletions. In addition to the germline events, somatic 16p loss-of-heterozygosity and 104 different somatic events are described. The pathogenicity of ARMC5 variants is established on the basis of their frequency in the general population, in silico predictions, familial segregation and tumor DNA sequencing.

CONCLUSIONS

This is the first extensive review of ARMC5 pathogenic variants. It shows that they are spread on the whole coding sequence. This is a valuable resource for genetic investigations of PBMAH and will help the interpretation of new missense substitutions that are continuously identified.

From the First Case Reports to KDM1A Identification: 35 Years of Food (GIP)-Dependent Cushing's Syndrome

Food-dependent Cushing's syndrome (FDCS) is a rare presentation of hypercortisolism from adrenal origin, mostly observed in primary bilateral macronodular adrenal hyperplasia (PBMAH) but also in some cases of unilateral adrenocortical adenoma. FDCS is mediated by the aberrant expression of glucose-dependent insulinotropic peptide (GIP) receptor (GIPR) in adrenocortical cells. GIP, secreted by duodenal K cells after food intake, binds to its ectopic adrenal receptor, and stimulates cortisol synthesis following meals. FDCS was first described more than 35 years ago, and its genetic cause in PBMAH has been recently elucidated: KDM1A inactivation by germline heterozygous pathogenic variants is constantly associated with a loss-of-heterozygosity of the short arm of chromosome 1, containing the KDM1A locus. This causes biallelic inactivation of KDM1A, resulting in the GIPR overexpression in the adrenal cortex. These new insights allow us to propose the KDM1A genetic screening to all PBMAH patients with signs of FDCS (low fasting cortisol that increases after a mixed meal or oral glucose load) and to all first-degree relatives of KDM1A variant carriers. Given that KDM1A is a tumor suppressor gene that has also been associated with monoclonal gammopathy of uncertain significance and multiple myeloma, the investigation of FDCS in the diagnostic management of patients with PBMAH and further genetic testing and screening for malignancies should be encouraged.

Presentation and management of patients with adrenal masses: a large tertiary centre experience

BACKGROUND

Adrenal masses are found in up to 5%-7% of adults. The 2016 European guidelines on the management of adrenal incidentalomas have standardised the workup of these patients, but evidence of their impact on clinical practice is lacking.

METHODS

Retrospective review of clinical presentation, radiological characteristics, and final diagnosis of a large cohort of patients with adrenal masses referred to a tertiary care centre 1998-2022. Sub-analysis compares outcomes before and after implementing the 2016 guidelines.

RESULTS

A total of 1397 patients (55.7% women; median age 60 years [interquartile range {IQR}, 49-70]) were included. Incidental discovery was the most frequent mode of presentation (63.7%) and 30.6% of patients had masses ≥ 4 cm (median 2.9 cm [IQR, 1.9-4.7]). Unenhanced computed tomography Hounsfield units (HU) were available for 763 patients; of these, 32.9% had heterogeneous masses or >20 HU. The most common diagnoses were adrenocortical adenoma (56.0%), phaeochromocytoma (12.7%), adrenocortical carcinoma (10.6%), and metastases (5.7%). At multivariable analysis, significant predictors of malignancy included >20 HU or heterogeneous density (odds ratio [OR] 28.40), androgen excess (OR 27.67), detection during cancer surveillance (OR 11.34), size ≥ 4 cm (OR 6.11), and male sex (OR 3.06). After implementing the 2016 guidelines, the number of adrenalectomies decreased (6.1% pre-2016 vs 4.5% post-2016) and the number of patients discharged increased (4.4% pre-2016 vs 25.3% post-2016) for benign non-functioning adrenal masses.

CONCLUSION

Implementing the 2016 guidelines positively impacted clinical practice, reducing unnecessary surgeries and increasing the discharge rate for benign adrenal masses, thereby preserving healthcare resources and patient burden.

Molecular and Genetics Perspectives on Primary Adrenocortical Hyperfunction Disorders

Adrenocortical disorders encompass a broad spectrum of conditions ranging from benign hyperplasia to malignant tumors, significantly disrupting hormone balance and causing a variety of clinical manifestations. By leveraging next-generation sequencing and in silico analyses, recent studies have uncovered the genetic and molecular pathways implicated in these transitions. In this review, we explored the molecular and genetic alterations in adrenocortical disorders, with a particular focus on the transitions from normal adrenal function to hyperfunction. The insights gained are intended to enhance diagnostic and therapeutic strategies, offering up-to-date knowledge for managing these complex conditions effectively.

Clinical Review: The Approach to the Evaluation and Management of Bilateral Adrenal Masses

OBJECTIVE

This white paper provides practical guidance for clinicians encountering bilateral adrenal masses.

METHODS

A case-based approach to the evaluation and management of bilateral adrenal masses. Specific clinical scenarios presented here include cases of bilateral adrenal adenomas, hemorrhage, pheochromocytomas, metastatic disease, myelolipomas, as well as primary bilateral macronodular adrenal hyperplasia.

RESULTS

Bilateral adrenal masses represent approximately 10% to 20% of incidentally discovered adrenal masses. The general approach to the evaluation and management of bilateral adrenal masses follows the same protocol as the evaluation of unilateral adrenal masses, determined based on the patient's clinical history and examination as well as the imaging characteristics of each lesion, whether the lesions could represent a malignancy, demonstrate hormone excess, or possibly represent a familial syndrome. Furthermore, there are features unique to bilateral adrenal masses that must be considered, including the differential diagnosis, the evaluation, and the management depending on the etiology. Therefore, considerations for the optimal imaging modality, treatment (medical vs surgical therapy), and surveillance are included. These recommendations were developed through careful examination of existing published studies as well as expert clinical opinion consensus.

CONCLUSION

The evaluation and management of bilateral adrenal masses require a comprehensive systematic approach which includes the assessment and interpretation of the patient's clinical history, physical examination, dynamic hormone evaluation, and imaging modalities to determine the key radiographic features of each adrenal nodule. In addition, familial syndromes should be considered. Any final treatment options and approaches should always be considered individually.

Bilateral Adrenocortical Nodular Disease and Cushing's Syndrome

Primary pigmented nodular adrenocortical disease (PPNAD) and bilateral macronodular adrenocortical disease (BMAD) are 2 forms of adrenocortical nodular diseases causing Cushing's syndrome but are 2 very distinct conditions. PPNAD, affecting mostly young patients with an almost constant severe Cushing's syndrome, is characterized by pigmented micronodules, usually less than 1 cm, not always visible on imaging. On the contrary, BMAD is predominantly diagnosed in the fifth and sixth decades, with highly variable degrees of cortisol excess, from mild autonomous cortisol secretion to overt Cushing's syndrome. BMAD presents as large bilateral adrenal macronodules, easily observed on imaging. Both diseases are often genetically determined: frequently PPNAD is observed in a multiple neoplasia syndrome, Carney complex, and a germline genetic defect is identified in around 80% of index cases, always affecting key actors of the cAMP/protein kinase A (PKA) pathway: mostly PRKAR1A, encoding the PKA 1-alpha regulatory subunit. On the other hand, BMAD appears mostly isolated, and 2 predisposing genes are known at present: ARMC5, accounting for around 20% of index cases, and the recently identified KDM1A, causing the rare presentation with food-dependent Cushing's syndrome, mediated by the ectopic expression of the glucose-dependent insulinotropic polypeptide receptor (GIPR) in adrenal nodules. GIPR was the first demonstrated receptor to illegitimately regulate cortisol secretion in nodular adrenocortical diseases, and a myriad of other receptors and paracrine signals were discovered afterward. The last 30 years were pivotal in the understanding of the genetics and pathophysiology of bilateral adrenocortical nodular diseases, leading to a personalized approach of these fascinating conditions.

Primary unilateral macronodular adrenal hyperplasia with concomitant glucocorticoid and androgen excess and KDM1A inactivation

BACKGROUND

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a rare cause of Cushing's syndrome. Individuals with PBMAH and glucose-dependent insulinotropic polypeptide (GIP)-dependent Cushing's syndrome due to ectopic expression of the GIP receptor (GIPR) typically harbor inactivating KDM1A sequence variants. Primary unilateral macronodular adrenal hyperplasia (PUMAH) with concomitant glucocorticoid and androgen excess has never been encountered or studied.

METHODS

We investigated a woman with a large, heterogeneous adrenal mass and severe adrenocorticotropic hormone-independent glucocorticoid and androgen excess, a biochemical presentation typically suggestive of adrenocortical carcinoma. The patient presented during pregnancy (22nd week of gestation) and reported an 18-month history of oligomenorrhea, hirsutism, and weight gain. We undertook an exploratory study with detailed histopathological and genetic analysis of the resected adrenal mass and leukocyte DNA collected from the patient and her parents.

RESULTS

Histopathology revealed benign macronodular adrenal hyperplasia. Imaging showed a persistently normal contralateral adrenal gland. Whole-exome sequencing of 4 representative nodules detected KDM1A germline variants, benign NM_001009999.3:c.136G > A:p.G46S, and likely pathogenic NM_001009999.3:exon6:c.865_866del:p.R289Dfs*7. Copy number variation analysis demonstrated an additional somatic loss of the KDM1A wild-type allele on chromosome 1p36.12 in all nodules. RNA sequencing of a representative nodule showed low/absent KDM1A expression and increased GIPR expression compared with 52 unilateral sporadic adenomas and 4 normal adrenal glands. Luteinizing hormone/chorionic gonadotropin receptor expression was normal. Sanger sequencing confirmed heterozygous KDM1A variants in both parents (father: p.R289Dfs*7 and mother: p.G46S) who showed no clinical features suggestive of glucocorticoid or androgen excess.

CONCLUSIONS

We investigated the first PUMAH associated with severe Cushing's syndrome and concomitant androgen excess, suggesting pathogenic mechanisms involving KDM1A.

Mild autonomous cortisol secretion: pathophysiology, comorbidities and management approaches

The majority of incidentally discovered adrenal tumours are benign adrenocortical adenomas and the prevalence of adrenocortical adenomas is around 1-7% on cross-sectional abdominal imaging. These can be non-functioning adrenal tumours or they can be associated with autonomous cortisol secretion on a spectrum that ranges from rare clinically overt adrenal Cushing syndrome to the much more prevalent mild autonomous cortisol secretion (MACS) without signs of Cushing syndrome. MACS is diagnosed (based on an abnormal overnight dexamethasone suppression test) in 20-50% of patients with adrenal adenomas. MACS is associated with cardiovascular morbidity, frailty, fragility fractures, decreased quality of life and increased mortality. Management of MACS should be individualized based on patient characteristics and includes adrenalectomy or conservative follow-up with treatment of associated comorbidities. Identifying patients with MACS who are most likely to benefit from adrenalectomy is challenging, as adrenalectomy results in improvement of cardiovascular morbidity in some, but not all, patients with MACS. Of note, diagnosis and management of patients with bilateral MACS is especially challenging. Current gaps in MACS clinical practice include a lack of specific biomarkers diagnostic of MACS-related health outcomes and a paucity of clinical trials demonstrating the efficacy of adrenalectomy on comorbidities associated with MACS. In addition, little evidence exists to demonstrate the efficacy and safety of long-term medical therapy in patients with MACS.

Approach to the Patient With Bilateral Adrenal Masses

Bilateral adrenal masses, increasingly encountered in clinical practice, manifest across diverse contexts, including incidental discovery, malignancy staging, and targeted imaging after hormonal diagnosis of adrenal disorders. The spectrum encompasses various pathologies, such as cortical adenomas, macronodular adrenal disease, pheochromocytomas, myelolipomas, infiltrative disorders, and primary and secondary malignancies. Notably, not all masses in both adrenal glands necessarily share the same etiology, often exhibiting diverse causes. Recently, the European Society of Endocrinology and the European Network for the Study of Adrenal Tumors updated guidelines, introduced a 4-option schema based on imaging, aiding in targeted hormonal testing and management. This "Approach to the Patient" review delves into the latest advancements in imaging, biochemical, and genetic approaches for the diagnostic and management nuances of bilateral adrenal masses. It provides insights and a contemporary framework for navigating the complexities associated with this clinical entity.

Consensus statement by the French Society of Endocrinology (SFE) and French Society of Pediatric Endocrinology & Diabetology (SFEDP) for the diagnosis of Cushing's syndrome: Genetics of Cushing's syndrome

Cushing's syndrome is due to overproduction of cortisol, leading to abnormal and prolonged exposure to cortisol. The most common etiology is Cushing disease, while adrenal causes are rarer. Knowledge of the genetics of Cushing's syndrome, and particularly the adrenal causes, has improved considerably over the last 10 years, thanks in particular to technical advances in high-throughput sequencing. The present study, by a group of experts from the French Society of Endocrinology and the French Society of Pediatric Endocrinology and Diabetology, reviewed the literature on germline genetic alterations leading to a predisposition to develop Cushing's syndrome. The review led to a consensus statement on genetic screening for Cushing disease and adrenal Cushing's syndrome.

Cushing's syndrome

Endogenous Cushing's syndrome results from excess glucocorticoid secretion, which leads to a myriad of clinical manifestations, comorbidities, and increased mortality despite treatment. Molecular mechanisms and genetic alterations associated with different causes of Cushing's syndrome have been described in the last decade. Imaging modalities and biochemical testing have evolved; however, both the diagnosis and management of Cushing's syndrome remain challenging. Surgery is the preferred treatment for all causes, but medical therapy has markedly advanced, with new drug options becoming available. Nevertheless, several comorbidities remain even after patient remission, which can affect quality of life. Accurate and timely diagnosis and treatment are essential for mitigating chronic complications of excess glucocorticoids and improving patient quality of life. In this Seminar, we aim to update several important aspects of diagnosis, complications, and treatment of endogenous Cushing's syndrome of all causes.

Prevalence and clinical features of armadillo repeat-containing 5 mutations carriers in a single center cohort of patients with bilateral adrenal incidentalomas

OBJECTIVE

We aimed to evaluate the prevalence of armadillo repeat-containing 5 (ARMC5) genetic defects in our cohort of bilateral adrenal incidentaloma (BAI) patients and to evaluate the possible existence of genotype-phenotype correlations.

DESIGN

Cross-sectional study.

SETTING

Tertiary care center.

PARTICIPANTS

72 BAI patients.

MAIN OUTCOME MEASURE(S)

The following data have been collected: morning adrenocorticotropic hormone (ACTH) concentrations; cortisol levels after 1 mg overnight dexamethasone suppression test (F-1mgDST); urinary free cortisol (UFC) levels; diameter of the adrenal masses; and the association with overweight/obesity, arterial hypertension, diabetes mellitus, dyslipidemia, cardiovascular events, unrelated neoplasia, osteoporosis, thyroid nodular disease, and primary hyperparathyroidism. A search for ARMC5 germline and somatic pathogenic variants was performed in all patients and in the adrenal tissue of patients operated on, respectively.

RESULTS

The prevalence of germline ARMC5 pathogenic variants among patients with mild autonomous cortisol secretion (MACS+, defined as F-1mgDST > 1.8 µg/dL) was 18.8%. No germline pathogenic variants were detected in patients without MACS. Moreover, somatic ARMC5 pathogenic variants were also found in the adrenal tissue of six patients without germline ARMC5 variants. The F-1mgDST levels >5 µg/dL predicted with a poor sensitivity but a 90.5% specificity in identifying the presence of ARMC5 germline pathogenic variants. We did not find any clinical parameter predictive of the ARMC5 mutation presence.

CONCLUSIONS

In MACS+ BAI patients, germline ARMC5 gene pathogenic variants are frequent. Further studies are needed to elucidate the pathophysiological role of somatic ARMC5 pathogenic variants on adrenal tumor development in otherwise wild-type (WT) patients.

Primary bilateral macronodular adrenocortical hyperplasia (PBMAH) patient with ARMC5 mutations

BACKGROUND

Primary bilateral macronodular adrenocortical hyperplasia (PBMAH) is a highly heterogeneous disease with divergent manifestations ranging from asymptomatic subclinical Cushing syndrome (CS) to overt Cushing syndrome with severe complications. ARMC5 mutations occur in 20 to 55% PBMAH patients usually with more severe phenotypes. Different ARMC5 mutations might be associated with diverse phenotypes of PBMAH.

CASE PRESENTATION

A 39-year-old man was admitted to our hospital with progressive weight gain and severe hypertension. He presented typical CS and its classical metabolic and bone complications like hypertension and osteoporosis. The laboratory results showed high levels of cortisol and low levels of ACTH. Low- and high-dosed dexamethasone suppression tests were negative. Contrast-enhanced computed tomography (CT) revealed multiple bilateral irregular macronodular adrenal masses. Adrenal venous sampling (AVS) confirmed that the right adrenal gland with larger nodules secreted more hormone that the left side did. Right adrenalectomy and subsequent contralateral subtotal resection were conducted. His blood pressure and CS symptoms as well as comorbidities including backache and muscle weakness improved. Whole exome sequencing identified one ARMC5 germline mutation (c.1855C > T, p. R619*), five ARMC5 somatic mutations (four novel mutations) in his right and left adrenal nodules.

CONCLUSIONS

This PBMAH patient was identified with one ARMC5 germline mutation and five different somatic ARMC5 mutations (four novel mutations) in the different nodules of the bilateral adrenal masses. AVS combined with CT imagine could be helpful to determine the dominant side for adrenalectomy. Genetic testing is important for the diagnosis and management of the patient with PBMAH.

Primary bilateral macronodular adrenal hyperplasia: A series of 32 cases and literature review

Primary bilateral macronodular adrenal hyperplasia (PBMAH) accounts for <2% of cases of Cushing's syndrome. The majority of patients present with no obvious steroid excess it means with autonomous cortisol secretion (ACS). The classic treatment for patients with overt Cushing's syndrome is bilateral adrenalectomy, but unilateral resection of the larger adrenal gland can result in clinical and/or biochemical remission in >90% of cases, especially in cases of ACS. In this article, a series of 32 cases with PBMAH is described. Most of the cases of PBMAH had ACS, except for one case with overt Cushing's syndrome. A study of aberrant receptors was performed in six patients, being negative in three cases, positive in the metoclopramide test in two cases and positive in the metoclopramide test and in the mixed meal test in another patient. The patient with overt Cushing's syndrome was treated with adrenostatic therapy achieving biochemical control, while two patients with ACS underwent unilateral adrenalectomy with resection of the largest adrenal gland, demonstrating hypercortisolism remission and improvement of cardiovascular risk factors after surgery. This article describes a series of 32 cases of PBMAH and offers a comprehensive review of PBMAH.

Impact of Morphology in the Genotype and Phenotype Correlation of Bilateral Macronodular Adrenocortical Disease (BMAD): A Series of Clinicopathologically Well-Characterized 35 Cases

Bilateral macronodular adrenocortical disease (BMAD) is characterized by the development of adrenal macronodules resulting in a pituitary-ACTH independent Cushing's syndrome. Although there are important similarities observed between the rare microscopic descriptions of this disease, the small series published are not representative of the molecular and genetic heterogenicity recently described in BMAD. We analyzed the pathological features in a series of BMAD and determined if there is correlation between these criteria and the characteristics of the patients. Two pathologists reviewed the slides of 35 patients who underwent surgery for suspicion of BMAD in our center between 1998 and 2021. An unsupervised multiple factor analysis based on microscopic characteristics divided the cases into 4 subtypes according to the architecture of the macronodules (containing or not round fibrous septa) and the proportion of the different cell types: clear, eosinophilic compact, and oncocytic cells. The correlation study with genetic revealed subtype 1 and subtype 2 are associated with the presence of ARMC5 and KDM1A pathogenic variants, respectively. By immunohistochemistry, all cell types expressed CYP11B1 and HSD3B1. HSD3B2 staining was predominantly expressed by clear cells whereas CYP17A1 staining was predominant on compact eosinophilic cells. This partial expression of steroidogenic enzymes may explain the low efficiency of cortisol production in BMAD. In subtype 1, trabeculae of eosinophilic cylindrical cells expressed DAB2 but not CYP11B2. In subtype 2, KDM1A expression was weaker in nodule cells than in normal adrenal cells; alpha inhibin expression was strong in compact cells. This first microscopic description of a series of 35 BMAD reveals the existence of 4 histopathological subtypes, 2 of which are strongly correlated with the presence of known germline genetic alterations. This classification emphasizes that BMAD has heterogeneous pathological characteristics that correlate with some genetic alterations identified in patients.

New advances in endocrine hypertension: from genes to biomarkers

Hypertension (HT) is a major cardiovascular risk factor that affects 10% to 40% of the general population in an age-dependent manner. Detection of secondary forms of HT is particularly important because it allows the targeted management of the underlying disease. Among hypertensive patients, the prevalence of endocrine HT reaches up to 10%. Adrenal diseases are the most frequent cause of endocrine HT and are associated with excess production of mineralocorticoids (mainly primary aldosteronism), glucocorticoids (Cushing syndrome), and catecholamines (pheochromocytoma). In addition, a few rare diseases directly affecting the action of mineralocorticoids and glucocorticoids in the kidney also lead to endocrine HT. Over the past years, genomic and genetic studies have allowed improving our knowledge on the molecular mechanisms of endocrine HT. Those discoveries have opened new opportunities to transfer knowledge to clinical practice for better diagnosis and specific treatment of affected subjects. In this review, we describe the physiology of adrenal hormone biosynthesis and action, the clinical and biochemical characteristics of different forms of endocrine HT, and their underlying genetic defects. We discuss the impact of these discoveries on diagnosis and management of patients, as well as new perspectives related to the use of new biomarkers for improved patient care.

Clinical, pathophysiologic, genetic and therapeutic progress in Primary Bilateral Macronodular Adrenal Hyperplasia

Patients with primary bilateral macronodular adrenal hyperplasia (PBMAH) usually present bilateral benign adrenocortical macronodules at imaging and variable levels of cortisol excess. PBMAH is a rare cause of primary overt Cushing's syndrome, but may represent up to one third of bilateral adrenal incidentalomas with evidence of cortisol excess. The increased steroidogenesis in PBMAH is often regulated by various G-protein coupled receptors aberrantly expressed in PBMAH tissues; some receptor ligands are ectopically produced in PBMAH tissues creating aberrant autocrine/paracrine regulation of steroidogenesis. The bilateral nature of PBMAH and familial aggregation, led to the identification of germline heterozygous inactivating mutations of the ARMC5 gene, in 20-25% of the apparent sporadic cases and more frequently in familial cases; ARMC5 mutations/pathogenic variants can be associated with meningiomas. More recently, combined germline mutations/pathogenic variants and somatic events inactivating the KDM1A gene were specifically identified in patients affected by GIP-dependent PBMAH. Functional studies demonstrated that inactivation of KDM1A leads to GIP-receptor (GIPR) overexpression and over or down-regulation of other GPCRs. Genetic analysis is now available for early detection of family members of index cases with PBMAH carrying identified germline pathogenic variants. Detailed biochemical, imaging, and co-morbidities assessment of the nature and severity of PBMAH is essential for its management. Treatment is reserved for patients with overt or mild cortisol/aldosterone or other steroid excesses taking in account co-morbidities. It previously relied on bilateral adrenalectomy; however recent studies tend to favor unilateral adrenalectomy, or less frequently, medical treatment with cortisol synthesis inhibitors or specific blockers of aberrant GPCR.

Primary bilateral macronodular adrenal hyperplasia: definitely a genetic disease

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is an adrenal cause of Cushing syndrome. Nowadays, a PBMAH diagnosis is more frequent than previously, as a result of progress in the diagnostic methods for adrenal incidentalomas, which are widely available. Although some rare syndromic forms of PBMAH are known to be of genetic origin, non-syndromic forms of PBMAH have only been recognized as a genetic disease in the past 10 years. Genomics studies have highlighted the molecular heterogeneity of PBMAH and identified molecular subgroups, allowing improved understanding of the clinical heterogeneity of this disease. Furthermore, the generation of these subgroups permitted the identification of new genes responsible for PBMAH. Constitutive inactivating variants in ARMC5 and KDM1A are responsible for the development of distinct forms of PBMAH. To date, pathogenic variants of ARMC5 are responsible for 20-25% of PBMAH, whereas germline KDM1A alterations have been identified in >90% of PBMAH causing food-dependent Cushing syndrome. The identification of pathogenic variants in ARMC5 and KDM1A demonstrated that PBMAH, despite mostly being diagnosed in adults aged 45-60 years, is a genetic disorder. This Review summarizes the important progress made in the past 10 years in understanding the genetics of PBMAH, which have led to a better understanding of the pathophysiology, opening new clinical perspectives.