Clinical identification of expressed proteins in adrenal medullary hyperplasia detected with hypertension.

Background: Hypertension remains a challenging public health problem worldwide, and adrenal gland-related diseases are one class of the major causes for secondary hypertension. Among them, one relatively rare pattern is adrenal hyperplastic hypertension caused by adrenal medullary hyperplasia (AMH), leading to excessive secretion of autonomic catecholamine. Given that the pathological changes of adrenal medulla are not well correlated to the onset and even severity of secondary hypertension, the molecular basis why some AMH patients are accompanied with hypertension remains unclear and is worth exploring. Aims: For this reason, this study aims at investigating differentially expressed proteins in clinical AMH tissue, with special focus on the potential contribution of these differentially expressed proteins to AMH development, in order to have a better understanding of mechanisms how AMH leads to secondary hypertension to some extent. Methods and results: To this end, AMH specimens were successfully obtained and verified through computed tomography (CT) and haematoxylin-eosin (HE) staining. Proteomic analyses of AMH and control tissues revealed 782 kinds of differentially expressed proteins. Compared with the control tissue, there were 357 types of upregulated proteins and 425 types of downregulated proteins detected in AMH tissue. Of interest, these differentially expressed proteins were significantly enriched in 60 gene ontology terms (P < 0.05), including 28 biological process terms, 14 molecular function terms, and 18 cellular component terms. Pathway analysis further indicated that 306 proteins exert their functions in at least one Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Western blotting showed enhanced expression of phenylethanolamine N- methyltransferase (PNMT), myelin protein zero (MPZ), and Ras-related protein Rab-3C (RAB3C), and reduced expression of cluster of differentiation 36 (CD36) observed in AMH tissue in comparison with controls. Conclusions: Clinical AMH specimens display a different proteomic profile compared to control tissue. Of note, PNMT, MPZ, RAB3C, and CD36 are found to differentially expressed and can be potential targets for AMH, providing a theoretical basis for mechanistic exploration of AMH along with hypertension.

Case Report: Three Rare Cases of Ectopic ACTH Syndrome Caused by Adrenal Medullary Hyperplasia.

Ectopic ACTH syndrome (EAS) accounts for 10-20% of endogenous Cushing's syndrome (CS). Hardly any cases of adrenal medullary hyperplasia have been reported to ectopically secrete adrenocorticotropic hormone (ACTH). Here we describe a series of three patients with hypercortisolism secondary to ectopic production of ACTH from adrenal medulla. Cushingoid features were absent in case 1 but evident in the other two cases. Marked hypokalemia was found in all three patients, but hyperglycemia and osteoporosis were present only in case 2. All three patients showed significantly elevated serum cortisol and 24-h urinary cortisol levels. The ACTH levels ranged from 19.8 to 103.0pmol/L, favoring ACTH-dependent Cushing's syndrome. Results of bilateral inferior petrosal sinus sampling (BIPSS) for case 1 and case 3 confirmed ectopic origin of ACTH. The extremely high level of ACTH and failure to suppress cortisol with high dose dexamethasone suppression test (HDDST) suggested EAS for patient 2. However, image studies failed to identify the source of ACTH secretion. Bilateral adrenalectomy was performed for rapid control of hypercortisolism. After surgery, cushingoid features gradually disappeared for case 2 and case 3. Blood pressure, blood glucose and potassium levels returned to normal ranges without medication for case 2. The level of serum potassium also normalized without any supplementation for case 1 and case 3. The ACTH levels of all three patients significantly decreased 3-6 months after surgery. Histopathology revealed bilateral adrenal medullary hyperplasia and immunostaining showed positive ACTH staining located in adrenal medulla cells. In summary, our case series reveals the adrenal medulla to be a site of ectopic ACTH secretion. Adrenal medulla-originated EAS makes the differential diagnosis of ACTH-dependent Cushing's syndrome much more difficult. Control of the hypercortisolism is mandatory for such patients.

Adrenal medullary hyperplasia with coexistent cerebral angiomas.

Sporadic adrenal medullary hyperplasia (AMH) is a rare entity and mimics pheochromocytoma clinically as well as pharmacologically. It is characterized by increase in adrenal medullary cells with the expansion of cells into areas normally not seen. A 59-year-old male presented with chronic hypertension and raised 24-h urinary normetanephrine levels. Radiological and clinical possibility of pheochromocytoma led to left transperitoneal laparoscopic adrenalectomy. Histopathology, however, showed increase in adrenal medullary to cortical ratio, further confirmed by immunohistochemistry. The absence of any well-defined lesion led to the diagnosis of AMH. Furthermore, on routine imaging, two asymptomatic cavernous hemangiomas were seen. We present this case to reiterate that AMH is an entity which should be considered as a differential for pheochromocytoma. Furthermore, the presence of asymptomatic cavernous hemangiomas in the cerebrum, in this case, makes it rarer since this sporadic association is seldom seen.

Renal tubular and adrenal medullary tumors in the 2-year rat study with canagliflozin confirmed to be secondary to carbohydrate (glucose) malabsorption in the 15-month mechanistic rat study.

During preclinical development of canagliflozin, an SGLT2 inhibitor, treatment-related pheochromocytomas, renal tubular tumors (RTT), and testicular Leydig cell tumors were reported in the 2-year rat toxicology study. In a previous 6-month rat mechanistic study, feeding a glucose free diet prevented canagliflozin effects on carbohydrate malabsorption as well as the increase in cell proliferation in adrenal medulla and kidneys, implicating carbohydrate malabsorption as the mechanism for tumor formation. In this chronic study male Sprague-Dawley rats were dosed orally with canagliflozin at high dose-levels (65 or 100 mg/kg/day) for 15 months and received either a standard diet or a glucose-free diet. Canagliflozin-dosed rats on standard diet showed presence of basophilic renal tubular tumors (6/90) and an increased incidence of adrenal medullary hyperplasia (35/90), which was fully prevented by feeding a glucose-free diet (no RTT's; adrenal medullary hyperplasia in ≤5/90). These data further confirm that kidney and adrenal medullary tumors in the 2-year rat study were secondary to carbohydrate (glucose) malabsorption and were not due to a direct effect of canagliflozin on these target tissues.

Frequency of Cushing's syndrome due to ACTH-secreting adrenal medullary lesions: a retrospective study over 10 years from a single center.

Cushing's syndrome due to ectopic adrenocorticotropic hormone production from adrenal medullary lesions has occasionally been described. We retrospectively reviewed all 164 cases of Cushing's syndrome and 77 cases of pheochromocytomas during 10 years. Of all cases with Cushing's syndrome, only two cases (1.2 %) were due to ectopic adrenocorticotropic hormone production from adrenal medullary lesions (one case of pheochromocytoma and one case of adrenal medullary hyperplasia). Of all pheochromocytomas only the above-mentioned case (1.3 %) also gave rise to an ectopic adrenocorticotropic hormone syndrome. The clinical presentation of adrenocorticotropic hormone-secreting pheochromocytoma and adrenal medullary hyperplasia can be anything from mild to dramatic. These are rare conditions important to bear in mind in the workup of a patient with Cushing's syndrome or with pheochromocytoma. The identification of ectopic adrenocorticotropic hormone secretion from adrenal medullary lesions can be life-saving.

Pathological and Genetic Characterization of Bilateral Adrenomedullary Hyperplasia in a Patient with Germline MAX Mutation.

In recent years, familial pheochromocytoma (PHEO) with germline mutations in the MAX (MYC associated factor X) gene has been reported in a few cases. Here, we investigated a 25-year-old patient with multiple PHEOs associated with a non-sense germline MAX mutation. Preoperative 18F-FDOPA PET/CT revealed bilateral adrenal involvement with multiple tumors. In addition, both adrenal glands were found to have diffuse or nodular adrenal medullary hyperplasia (AMH), a histopathological feature previously described as a precursor of MEN2- and SDHB-related PHEOs but not MAX. After bilateral adrenalectomy, different paraffin-embedded and frozen samples were analyzed for allelic imbalances of the MAX gene using allelic quantification by pyrosequencing. The expression of the protein MAX was studied by immunohistochemistry. All PHEOs but also nodular AMH exhibited a loss of the normal allele. By contrast, the diffuse AMH did not show loss-of-heterozygosity. Nevertheless, immunohistochemistry demonstrated loss of protein MAX expression in all samples including diffuse hyperplasia, suggesting a causative role of MAX mutation for both PHEOs and AMH. The present case shows that both nodular and diffuse AMH belongs to the spectrum of MAX-related disease. These data support the possible continuum between nodular AMH and PHEO, expanding the qualification of micro-PHEO to nodular AMH.

Changes of adrenomedullin and natriuretic peptides in patients with adrenal medullary hyperplasia prior to and following pharmacological therapy and adrenalectomy.

The aim of the present study was to investigate the pathophysiological functions of adrenomedullin (ADM), atrial and brain natriuretic peptides (ANP and BNP) in patients with adrenal medullary hyperplasia (AMH). Plasma ADM, ANP and BNP concentrations were measured in 20 patients with AMH, 35 patients with essential hypertension (EH), and 40 healthy control subjects. Following effective antihypertensive therapy, the values in AMH and EH patients were measured again and laparoscopic adrenalectomy was performed for AMH patients. At 2 weeks after surgery, the three peptides were measured again. The AMH patients had higher plasma concentrations of ADM, ANP and BNP compared with the EH and control subjects. There were significant differences in the values of ADM, ANP and BNP between adrenal vein and inferior vena cava and between AMH and contralateral adrenal vein. Plasma ADM concentration was correlated with serum epinephrine and norepinephrine and urine vanillylmandelic acid, in addition to systolic and diastolic blood pressure, left ventricular ejection fraction, left ventricular mass index and ANP and BNP values in the AMH group. Following antihypertensive treatment, ADM, ANP and BNP were significantly decreased in EH patients, but remained unchanged in AMH subjects. However, these concentrations significantly decreased following surgery. Therefore, the present results suggest that ADM, ANP and BNP may be involved in regulating adrenal medulla functions.

Adrenal medullary hyperplasia is a precursor lesion for pheochromocytoma in MEN2 syndrome.

Adrenal medullary hyperplasias (AMHs) are adrenal medullary proliferations with a size < 1 cm, while larger lesions are considered as pheochromocytoma (PCC). This arbitrary distinction has been proposed decades ago, although the biological relationship between AMH and PCC has never been investigated. Both lesions are frequently diagnosed in multiple endocrine neoplasia type 2 (MEN2) patients in whom they are considered as two unrelated clinical entities. In this study, we investigated the molecular relationship between AMH and PCC in MEN2 patients. Molecular aberrations of 19 AMHs and 13 PCCs from 18 MEN2 patients were determined by rearranged during transfection (RET) proto-oncogene mutation analysis and loss of heterozygosity (LOH) analysis for chromosomal regions 1p13, 1p36, 3p, and 3q, genomic areas covering commonly altered regions in RET-related PCC. Identical molecular aberrations were found in all AMHs and PCCs, at similar frequencies. LOH was seen for chromosomes 1p13 in 8 of 18 (44%), 1p36 in 9 of 15 (60%), 3p12-13 in 12 of 18 (67%), and 3q23-24 in 10 of 16 (63%) of AMHs, and for chromosome 1p13 in 13 of 13 (100%), 1p36 in 7 of 11 (64%), 3p12-13 in 4 of 11 (36%), and 3q23-24 in 11 of 12 (92%) of PCCs. Our results indicate that AMHs are not hyperplasias and, in clinical practice, should be regarded as PCCs, which has an impact on diagnosis and treatment of MEN2 patients. We therefore propose to replace the term AMH by micro-PCC to indicate adrenal medullary proliferations of less than 1 cm.

An Adrenal Cortical Adenoma with Adrenal Medullary Hyperplasia / 대한내과학회지

The relationship between the adrenal cortex and medulla has been studied since the 1960s. Rarely, a patient with an adrenal cortical adenoma presents with the findings of pheochromocytoma. However, there has been no report of a case with the clinical features of pheochromocytoma showing the pathological features of an adrenal cortical adenoma with medullary hyperplasia on histological examination. We report a 59-year-old-man who was shown to have an adrenal cortical adenoma, with medullary hyperplasia, during a diagnostic work up for pheochromocytoma.

Adrenal Medullary Hyperplasia with Coexisting Adrenal Cortical Adenoma / 대한내분비외과학회지

Adrenal medullary hyperplasia is an increase in the mass of the adrenal medullary cells. We report a case of a 38-year-old man presenting with pheochromocytoma-like symptoms who was preoperatively misdiagnosed with pheochromocytoma. Hypertension was associated with an intracranial hemorrhage evident in a brain computed tomography scan, in which no obvious pituitary gland enlargement was detected. An abdominopelvic CT revealed a solitary tumor in the right adrenal gland with no obvious enlargement of the contralateral adrenal gland or sympathetic chains. Lab results showed increased levels of urinary metanephrines. Based on clinical data, the patient underwent a laparoscopic right adrenalectomy bases on a diagnosis of pheochromocytoma. The patient was finally diagnosed with adrenal medullary hyperplasia with coexisting ipsilateral non-functioning adrenal cortical adenoma. Postoperatively, blood pressure and lab results were maintained in the normal range and the patient was symptomatically free during the follow-up period.

Hypercatecholaminism(report of 95 cases) / 中华泌尿外科杂志

Objective To evaluate the improvement of diagnosis and treatment of hypercatecholaminism. Methods A total of 95 cases of hypercatecholaminism were reviewed.Of them 74 cases were of pheochromocytoma and 21 cases were of adrenal medullary hyperplasia (AMH).In pheochromocytoma group,67 cases (90.5%) had symptom of hypertension.Increase in 24 h urinary VMA occurred in 62 cases (83.8%) and elevated urinary catecholamine level in 67(90.5%).All thses had positive findings of ultrasound,CT scan and MRI.In AMH group,all the patients were hypertensive and their 24 h urinary VMA was increased.Most of them (15/16) had higher urinary catecholamine level than normal;14 out of the 21 cases had positive findings of B-ultrasound examination. Results Surgical operations were performed in the 74 patients with pheochromocytoma including 9 cases of extra-drenal pheochromocytoma.Of them 5 cases were confirmed as malignant pheochromocytoma.In the 21 cases of AMH,18 undewent surgical operation.Of them 12 received unilateral resection and 6 received bilateral resection of adrenal gland.The pathological examination confirmed the diagnosis of AMH. Conclusions The diagnosis of pheochromocytoma should be focused on endocrinological examination,ie,qualitative examination,whereas it is diffucult to localize the lesion in AMH compared with pheochromocytoma.The establishment of notion of AMH as an isolated clinicopathological entity broadens and perfects the theory of hypercatecholaminism.

ADRENAL MEDULLARY HYPERPLASIA: CLINICAL ANALYSIS OF 4 CASES / 解放军医学杂志

Adrenal medullary hyperplasia (AMH) is a rare cause of secondary hypertension. Herein we analysed clinical manifestation of 4 cases. The clinical and biochemical features of AMH were similar to those of pheochromocytoma. 131 I MIBG scintigram and CT scanning were helpful to make differential diagnosis. Etiology, diagnosis and treatment of AMH were discussed.