Analysis of clinical and pathological features of primary bilateral macronodular adrenocortical hyperplasia compared with unilateral cortisol-secreting adrenal adenoma

Bilateral macronodular adrenocortical disease: a single centre experience

Background

Data on bilateral macronodular adrenocortical disease (BMAD) with respect to computed tomography (CT) scan characteristics (attenuation and washout) and long-term follow-up are limited. This study aims to describe BMAD patients managed in a single centre.

Methods

BMAD was defined by the presence of bilateral adrenal macronodules (>1 cm) on CT. Clinical, biochemical, radiological, genetic characteristics, management and follow-up of 22 BMAD patients were studied retrospectively.

Results

The median age (range) at presentation was 49.5 (23-83) years, predominantly observed in females (16/22). Eighteen (82%) patients were incidentally diagnosed (11 with mild autonomous cortisol secretion (MACS) and seven non-secretory), three (13.7%) presented with overt Cushing's syndrome (CS), and one (4.5%) had androgen excess (without CS features). On CT, the dominant nodule's median (range) size was 2.6(1.6-9.5) cm. 77.8% (14/18) of adrenal nodules were lipid-rich, and 93.3% (14/15) of the nodules exhibited good washout. Genetic analysis was available for eight patients; one had a novel germline ARMC5 variant, and two had MEN-1 gene mutations. Three overt CS and one androgen-secreting patient underwent total bilateral adrenalectomy; histopathology showed macronodular hyperplasia with internodular hypertrophy. Only one (1/8) patient from the MACS group developed a new comorbidity (diabetes mellitus) after a median follow-up of 6.4 (0.5-12.4) years, while none of the non-secretory group patients developed new comorbidities after a median follow-up of 1.4 (0.8-12.2) years.

Conclusion

Most BMAD patients presented without overt hormonal excess, and none developed overt CS on follow-up. Detailed CT characteristics of BMAD nodules may help in radiological diagnosis in bilateral adrenal incidentalomas.

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.

Beyond symptomatology: A comparative analysis of unilateral and bilateral macronodular mild autonomous cortisol secretion

OBJECTIVE

To investigate the clinical, laboratory findings and signal intensity index (SII) on magnetic resonance imaging (MRI) of patients with bilateral and unilateral macronodular mild autonomous cortisol secretion (MACS).

PATIENTS AND MEASUREMENTS

Clinical and laboratory findings of 81 patients with MACS were examined from retrospective records. SII of adenomas and internodular areas were evaluated by MRI. The unilateral group included patients with an adrenal macronodule (≥1 cm) in a single adrenal gland, while the bilateral group included patients with at least one macronodule in both adrenal glands.

RESULTS

In total, 46 patients were in the unilateral (57%), while 35 (43%) patients were in the bilateral groups. The dehydroepiandrosterone sulphate (DHEA-S) level was lower in the unilateral than in the bilateral group (p < .001). The presence of type 2 diabetes mellitus (T2DM), glycosylated haemoglobin (HbA1c) and low-density lipoprotein (LDL) concentrations were higher in the bilateral group (p < .05). However, no significant difference was detected in terms of adrenocorticotropic hormone (ACTH) and overnight 1 mg dexamethasone suppression test (DST) between the two groups (p > .05). There was no difference in SII between adenomas within the same patient, as well as between the unilateral and bilateral groups (p > .05). Logistic regression analysis based on the differentiation between unilateral and bilateral macronodular MACS demonstrated that DHEA-S, HbA1c and LDL concentrations were associated factors.

CONCLUSION

DHEA-S levels may not be as suppressed in patients with bilateral macronodular MACS as compared to those with unilateral adenoma. T2DM and hypercholesterolaemia have a higher frequency in bilateral patients. However, ACTH, overnight 1 mg DST and SII may not provide additional information for differentiation of bilaterality and unilaterality.

Molecular tools for diagnosing diseases of the adrenal cortex

PURPOSE OF REVIEW

The adrenal glands produce some of the most essential for life hormones, including cortisol and other steroids, and catecholamines. The former is produced from the adrenal cortex, whereas the latter is from the medulla. The two parts are anatomically and functionally distinct and it would be impossible in the context of one short article to cover all molecular updates on both the cortex and the medulla. Thus, in this review, we focus on the molecular tools available for diagnosing adrenocortical diseases, such as adrenal insufficiency, Cushing and Conn syndromes, and their potential for advancing medical care and clinical outcome.

RECENT FINDINGS

The advent of next generation sequencing opened doors for finding genetic diseases and signaling pathways involved in adrenocortical diseases. In addition, the combination of molecular data and clinicopathologic assessment might be the best approach for an early and precise diagnosis contributing to therapeutic decisions and improvement of patient outcomes.

SUMMARY

Diagnosing adrenocortical diseases can be challenging; however, the progress of molecular tools for adrenocortical disease diagnosis has greatly contributed to early detection and to meliorate patient outcomes.

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.

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.

Cushing´s syndrome due to bilateral adrenal cortical disease: Bilateral macronodular adrenal cortical disease and bilateral micronodular adrenal cortical disease

Cushing´s syndrome (CS) secondary to bilateral adrenal cortical disease may be caused by bilateral macronodular adrenal cortical disease (BMACD) or by bilateral micronodular adrenal cortical disease (miBACD). The size of adrenal nodules is a key factor for the differentiation between these two entities (>1cm, BMACD and <1cm; miBACD). BMACD can be associated with overt CS, but more commonly it presents with autonomous cortisol secretion (ACS). Surgical treatment of BMACD presenting with CS or with ACS and associated cardiometabolic comorbidities should be the resection of the largest adrenal gland, since it leads to hypercortisolism remission in up to 95% of the cases. Medical treatment focused on the blockade of aberrant receptors may lead to hypercortisolism control, although cortisol response is frequently transient. miBACD is mainly divided in primary pigmented nodular adrenocortical disease (PPNAD) and isolated micronodular adrenocortical disease (i-MAD). miBACD can present at an early age, representing one of the main causes of CS at a young age. The high-dose dexamethasone suppression test can be useful in identifying a paradoxical increase in 24h-urinary free cortisol, that is a quite specific in PPNAD. Bilateral adrenalectomy is generally the treatment of choice in patients with overt CS in miBACD, but unilateral adrenalectomy could be considered in cases with asymmetric disease and mild hypercortisolism. This article will discuss the clinical presentation, genetic background, hormonal and imaging features and treatment of the main causes of primary bilateral adrenal hyperplasia associated with hypercortisolism.