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Primary bilateral macronodular adrenal hyperplasia (PBMAH), characterized by bilateral benign adrenal macronodules (>1 cm) potentially responsible for variable levels of cortisol excess, is a rare and heterogeneous disease. However, its frequency increases due to incidentally diagnosed cases on abdominal imaging carried out for reasons other than suspected adrenal disease. Mostly isolated, it can also be associated with dominantly inherited genetic conditions in rare cases. Considering the bilateral nature of adrenal involvement and the description of familial cases, the search of a genetic predisposition has led to the identification of germline heterozygous inactivating mutations of the putative tumor suppressor gene ARMC5, causing around 25% of the apparent sporadic cases. Rigorous biochemical and imaging assessment are key elements in the management of this challenging disease in terms of diagnosis. Treatment is reserved for symptomatic patients with overt or subclinical Cushing syndrome, and was historically based on bilateral adrenalectomy, which nowadays tends to be replaced by unilateral adrenalectomy or lifelong treatment with cortisol synthesis inhibitors.

The last 10 years have produced an amazing number of significant discoveries in the field of adrenal endocrinology. The development of the adrenal gland was linked to specific molecules. Cortisol-producing lesions were associated mostly with defects of the cyclic AMP (cAMP) signaling pathway, whereas aldosterone-producing lesions were found to be the result of defects in aldosterone biosynthesis or the potassium channel KCNJ5 and related molecules. Macronodular adrenal hyperplasia was linked to ARMC5 defects and new genes were found to be involved in adrenocortical cancer (ACC). The succinate dehydrogenase (SDH) enzyme was proven to be the most important molecular pathway involved in pheochromocytomas, along with several other genes. Adrenomedullary tumors are now largely molecularly elucidated. Unfortunately, most of these important discoveries have yet to produce new therapeutic tools for our patients with adrenal diseases: ACC in its advanced stages remains largely an untreatable disorder and malignant pheochromocytomas are equally hard to treat. Thus, the challenge for the next 10 years is to translate the important discoveries of the previous decade into substantial advances in the treatment of adrenal disorders and tumors.

Management of patients with bilateral adrenal masses and ACTH-independent Cushing’s syndrome (AICS) is challenging, as bilateral adrenalectomy can lead to steroid dependence and lifelong risk of adrenal crisis. Adrenal venous sampling (AVS) has been previously reported to facilitate lateralization for guiding adrenalectomy. The aim of the current study was to investigate the utility of AVS using protocol from study by Young et al. in the management of patients with bilateral adrenal masses and AICS. A retrospective review of all patients with bilateral adrenal masses and AICS who underwent AVS from 2008 to 2016 was performed. AVS for cortisol and epinephrine was performed with dexamethasone suppression. The adrenal vein to peripheral vein cortisol ratios and side-to-side cortisol lateralization ratios were calculated. AVS was successful in 8 of 9 patients. All 8 patients had AVS results indicating bilateral cortisol hypersecretion. Six patients underwent adrenalectomy: 3 had unilateral adrenalectomy of the larger size mass, 2 had bilateral adrenalectomy (both sides >4 cm.) and 1 had stepwise bilateral adrenalectomy. Final pathology revealed macronodular adrenal hyperplasia in all 6 patients that underwent surgery. AVS was useful in excluding a unilateral adenoma as the source of AICS in this study of patients with bilateral adrenal masses and AICS. However, adrenal mass size influenced surgical decision making more than AVS results. More data are needed before AVS can be advocated as essential for management of patients with bilateral adrenal masses and AICS.

ARMC5 mutations have recently been identified as a common genetic cause of primary bilateral macronodular adrenal hyperplasia (PBMAH). We aimed to assess the prevalence of ARMC5 germline mutations and correlate genotype with phenotype in a large cohort of PBMAH patients. A multicenter study was performed, collecting patients from different endocrinology units in Italy. Seventy-one PBMAH patients were screened for small mutations and large rearrangements in the ARMC5 gene: 53 were cortisol-secreting (two with a family history of adrenal hyperplasia) and 18 were non-secreting cases of PBMAH. Non-mutated and mutated patients’ clinical phenotypes were compared and related to the type of mutation. A likely causative germline ARMC5 mutation was only identified in cortisol-secreting PBMAH patients (one with a family history of adrenal hyperplasia and ten apparently sporadic cases). Screening in eight first-degree relatives of three index cases revealed four carriers of an ARMC5 mutation. Evidence of a second hit at somatic level was identified in five nodules. Mutated patients had higher cortisol levels (p = 0.062), and more severe hypertension and diabetes (p

Idiopathic hyperaldosteronism (IHA) due to bilateral adrenal hyperplasia is the most common subtype of primary aldosteronism (PA). The pathogenesis of IHA is still unknown, but the bilateral disease suggests a potential predisposing genetic alteration. Heterozygous germline mutations of armadillo repeat containing 5 (ARMC5) have been shown to be associated with hypercortisolism due to sporadic primary bilateral macronodular adrenal hyperplasia and are also observed in African-American PA patients. We investigated the presence of germline ARMC5 mutations in a group of PA patients who had bilateral computed tomography-detectable adrenal alterations. We sequenced the entire coding region of ARMC5 and all intron/exon boundaries in 39 patients (37 Caucasians and 2 black Africans) with confirmed PA (8 unilateral, 27 bilateral and 4 undetermined subtype) and bilateral adrenal lesions. We identified 11 common variants, 5 rare variants with a minor allele frequency

Management of patients with bilateral adrenal masses and corticotropin (ACTH)-independent Cushing syndrome (CS) or subclinical CS is problematic. We report our experience with adrenal venous sampling (AVS) in the evaluation of 10 patients with bilateral masses who had ACTH-independent CS or subclinical CS. Ten patients (9 women, 1 man, mean age 56.4 years) with bilateral adrenal masses and ACTH-independent CS (n = 3) or subclinical CS (n = 7) underwent AVS. Autonomous cortisol secretion was documented in all cases with suppressed serum ACTH concentrations and lack of cortisol suppression with dexamethasone administration. Adrenal venous sampling was performed on the second day of dexamethasone administration. Cortisol and epinephrine levels were measured from each adrenal vein (AV) and from a peripheral vein (PV). Mean (± SD) maximal diameter of the adrenal masses on computed tomography was 3.3 ± 1.3 cm (range: 1.2–6.0 cm). Successful catheterization was confirmed with AV:PV epinephrine gradients. A cortisol AV:PV gradient >6.5 was consistent with a cortisol-secreting adenoma in 11 adrenal glands; 5 patients had clinically important bilateral autonomous cortisol hypersecretion, 3 had bilateral cortisol-secreting adenomas, and 2 had ACTH-independent macronodular adrenal hyperplasia. Adrenal venous sampling-guided adrenalectomy was completed in all 10 patients—2 patients had total bilateral adrenalectomy and 2 others had subtotal bilateral adrenalectomy. During a mean follow-up of 36.1 months (range: 0.7–123 months), CS or clinically important cortisol secretory autonomy did not recur. Adrenal venous sampling contributed to the localization of autonomous hypercortisolism in the setting of ACTH-independent CS or subclinical CS in patients with bilateral adrenal masses.

Cortisol secretion in ACTH independent bilateral macronodular adrenal hyperplasia (AIMAH) can be regulated by aberrant adrenal receptors. We describe a patient with Cushing's syndrome (CS) due to AIMAH and concomitant Class IV congestive heart failure (CHF). Clinical testing for the presence of aberrant receptors revealed a pronounced serum cortisol (257%) and aldosterone response (212%) to the administration of ACTH and a partial serum cortisol (35%) and aldosterone (106%) response to upright posture. This suggested the possible presence of aberrant hormone receptors for ACTH [melanocortin 2 receptor (MC2-R)], vasopressin, catecholamines or angiotensin II (AT-II) on the patient's adrenal glands. Adrenal tissue from the patient demonstrated an eight-fold increased expression of MC2-R compared to normal adrenal tissue. This increased expression was consistent with the increase in cortisol and aldosterone seen in response to exogenous ACTH. We propose that the severe CHF resulted in activation of the renin-angiotensin system, with an increased production of AT-II. The elevated circulating levels of AT-II may have led to increased expression of MC2-R on the patient's adrenal glands and increased responsiveness to ACTH. This unusual case of CS may elucidate a heretofore unknown mechanism for the development of AIMAH.

In recent years, a novel understanding of the pathophysiology of adrenal Cushing's syndrome has emerged. The ectopic or aberrant expression of G-protein-coupled hormone receptors in the adrenal cortex was found to play a central role in the regulation of cortisol secretion in ACTH-independent macronodular adrenal hyperplasia (AIMAH) and in some unilateral adrenal adenomas. Various aberrant receptors, functionally coupled to steroidogenesis, have been reported: GIP, vasopressin, beta-adrenergic, LH/hCG, and serotonin receptors have been best characterized, but angiotensin, leptin, glucagon, IL-1 and TSH receptors have also been described. The molecular mechanisms responsible for the aberrant expression of these receptors are currently unknown. One or many of these aberrant receptors are present in most cases of AIMAH and in some cases of adrenal adenomas with overt or sub-clinical secretion of cortisol. Clinical protocols to screen for such aberrant receptors have been developed and should be performed in all patients with AIMAH. The identification of such aberrant regulation of steroidogenesis in AIMAH provides the novel opportunity to treat some of these patients with pharmacological agents that either suppress the endogenous ligand or block the aberrant receptor, thus avoiding bilateral adrenalectomy.

This report describes a rare case of ACTH-independent macronodular adrenal hyperplasia (AIMAH) arisen with symptomatic severe hypertension and hypokaliemia. A 55-year-old man was admitted to hospital with a clinical picture characterized by several episodes of transient ischemic attacks (TIA) and right hemiplegia, related to severe arterial hypertension. Laboratory tests showed urinary levels of catecholamines, metanephrines and vanillylmandelic acid (VMA) in normal range; high urinary free cortisol excretion, elevated serum cortisol with loss of the circadian rhythm and low ACTH plasma levels. ACTH failed to respond to CRH administration. Serum cortisol levels were not modified after high doses of dexamethasone. MRI showed bilateral macronodular hyperplasia of adrenal glands, whereas pituitary-MRI did not show tumoral lesions. Therefore, ACTH-independent macronodular hyperplasia was suspected. Though obese, the patient had no typical Cushing habit, and symptomatic hypertension with hypokaliemia was the only clinical evidence for this rare kind of Cushing's syndrome. After obtaining a satisfactory control of blood pressure, the patient was successfully submitted to laparoscopic bilateral adrenalectomy and underwent complete clinical remission. The histology showed adrenal macronodular hyperplasia. During the twenty-four month follow-up, the patient had no further transient ischemic attacks or need of glucocorticoid replacement therapy and withdrew the antihypertensive drugs.

ACTH-independent macronodular adrenal hyperplasia (AIMAH) is a rare disorder and an unusual cause of Cushing s syndrome, of which familial transmission has rarely been reported. In this study, a mother and her son, the former affected with definite AIMAH and the latter with possible AIMAH, are described. Although the mother manifested overt Cushing s syndrome, her son remained with no stigmata of Cushing s syndrome except for bilateral adrenal tumor and mild hypertension, and a full suppression of plasma cortisol by lowdose dexamethasone was observed in him. Recently, aberrant expression of adrenal receptors for various ligands has been noted in AIMAH patients. In our cases, provocation tests in vivo suggested that AVP and catecholamines promoted cortisol production through V1a and/or V1b receptors and via beta-adrenergic receptor, respectively. Reverse transcriptional-PCR analysis of the operated adrenal tissues of mother revealed the abnormal expression of mRNA of receptors for V1b, V2, and LH/hCG, none of which was observed in a normal control. Inherited AIMAH is very rare, and the son might be at the earliest developmental stage of AIMAH among the cases reported so far. An intervention could be tried to prevent the development of overt Cushing s syndrome by suppression of the possible endogenous ligands or by blockade of the receptors that may be aberrantly expressed in his adrenal glands.

With increasing case reports, it has been indicated that some cases with adrenocorticotropic hormone (ACTH)-independent macronodular adrenal hyperplasia (AIMAH) show abnormal responses in cortisol to various stimulation tests. Here we report a case of AIMAH that showed an aberrant response to angiotensin II via AT1 receptor in cortisol hypersecretion. A 53-yr-old man was admitted to our division seeking further examinations for the possible diagnosis of Cushing's syndrome. He had hypertension, diabetes mellitus, and physical stigmata, such as moon face and central obesity. His plasma ACTH level was undetectable, and plasma cortisol level was high. Plasma cortisol showed no normal diurnal rhythm and was not suppressed after the administration of 8 mg of dexamethasone. Abdominal computed tomography demonstrated nodular enlargement of bilateral adrenal glands. He was diagnosed with Cushing's syndrome owing to AIMAH. An injection of arginine vasopressin (AVP) increased plasma cortisol and aldosterone levels, whereas ACTH remained undetectable. After 4 h in an upright position, plasma cortisol and aldosterone levels were increased. Pretreatment with candesartan, angiotensin II receptor AT1 antagonist, blocked the increase in plasma cortisol level. These results suggested a possibility of adrenal hypersensitivity to angiotensin II and AVP in cortisol secretion. Bilateral laparoscopic adrenalectomy was performed. The histological findings of the specimen were compatible with AIMAH. In summary, we have made the first report on a case of AIMAH with possible hypersensitivity to angiotensin II.

We read with interest an article published recently in the World Journal of Surgery regarding the role of unilateral adrenalectomy in ACTH-independent macronodular adrenal hyperplasia (AIMAH) [1]. In our institution, we have experience with a few cases of AIMAH including the familial type that were all treated by bilateral adrenalectomy [2–4]. Among them, we initially treated one case of AIMAH by unilateral adrenalectomy; however, successive completion adrenalectomy was required owing to the detection of hypersecretion of cortisol in the remaining adrenal gland during follow-up [3]. A 39-year-old Asian woman was admitted to our hospital for evaluation and treatment of AIMAH. She had typical cushingoid features and hypertension. The 24-hr urinary free cortisol was 646 lg (20–90 lg/day). ACTH was not detectable. The computed tomography scan showed 2and 3-cm ovoid masses in both adrenal glands. Stimulation with mixed meal, arginine-vasopressin, luteinizing hormone, b-adrenergic agonist, serotonin, and upright posture did not change her cortisol secretion. Selective adrenal venous sampling was performed according to current recommendations [5]. It revealed a localized hyperfunctioning tumor in the left adrenal gland (Fig. 1). After laparoscopic left adrenalectomy was performed, the hypertension and cushingoid features disappeared, and the 24-hr urinary free cortisol level returned to normal. Thereafter, we have checked serial blood pressure measurements, the 24-hr urinary free cortisol level, and the size of the remaining adrenal gland. Two years after the left adrenalectomy, the patient became hypertensive again with an elevated 24-hr urinary free cortisol level and evidence of enlargement of the right adrenal gland. Completion adrenalectomy was performed laparoscopically. The patient is currently on replacement therapy with physiologic doses of steroid hormones. Many studies are underway to help define the pathophysiology of AIMAH, especially with respect to the underlying mechanisms of adrenal autonomy, including ectopic and eutopic expression of several candidate receptor genes in the adrenal gland [6]. When the molecular pathophysiology of AIMAH is completely understood, medical treatment with specific antagonizing agents or

Adrenal function: Bilateral macronodular adrenal hyperplasia—new genetic and pathophysiological insights

Sir, In the adult patient with Cushing's syndrome very low plasma ACTH levels have been taken to rule out the presence of adrenal hyperplasia. Hence deter­ mination of plasma ACTH concentrations is crucial in selecting the rational therapy in Cushing's syndrome. However, Malehoff et al. recently described a novel syndrome: Adrenocorticotropin­ independent bilateral macronodular adrenal hyperplasia (1). We describe another case of apparently ACTH­ independent adrenal hyperplasia: the patient was a 63-year-old woman who had been hospitalized 12 yr earlier because of severe spinal osteopenia. At that time the urinary excretion of hydroxy­ corticosteroids was slightly supranormal. There was reportedly no clinical evidence of hypercorticism. No further studies were undertaken. She was readmitted in 1989 because of persistent edema. Because of atypical abdominal pains an abdominal CT was performed. Both adrenal glands were enlarged. The urinary excretion of cortisol was elevated (914-970 nmol/24 h, normal below 235 nmol/24 h). Plasma cortisol concentration was not suppressed after administration of 2 mg dexamethasone at midnight (plasma cortisol at 08:00: 642 nmol/I). Plasma ACTH concentrations were measured on four occasions and were consistently undetectable (radioimmunoassay using WHO ACTH standard 74/555 as reference). An adrenal 1311-cholesterol scintigraphy revealed intense accumulation in the right adrenal gland, whereas almost no activity was seen in the contralateral gland. The patient was referred to this department. On admission the patient was in poor condition, hypotensive, stuporous with insufficient respiration. Except for typical skin atrophy and extensive suggillations no typical cushingoid features were noted. Septic shock was suspected and later confirmed by isolation of B. fragilis in blood cultures. Despite antibiotic treatment her general conditions remained poor and a complete investigation was not possible. The urinary excretion ranged between 1022 and 3180 nmol/24 h. A second adrenal 1311-cho­ lesterol scintigraphy was performed, the result being identical to that of the first study. Five blood sampies

An 11 yr old white male with severe hypertension (150-170/100-120), hypokalemia (2.6-2.9 mEq/L) and suppressed plasma renin (PRA)(