An unusual case of ectopic corticotrophin-releasing hormone syndrome caused by an adrenal noncatecholamine-secreting pheochromocytoma: a case report.

BACKGROUND: Pheochromocytoma, especially for noncatecholamine-secreting pheochromocytoma, is an extremely rare cause of ectopic corticotrophin-releasing hormone (CRH) syndrome. CASE PRESENTATION: A 27-year-old Chinese woman was administered dexamethasone for a skin allergy, but her general condition rapidly deteriorated over a month. She was subsequently hospitalized for typical clinical features of Cushing's syndrome. Endocrinological investigation confirmed severe hypercortisolism along with elevated plasma adrenocorticotropin hormone (ACTH). However, magnetic resonance imaging (MRI) revealed no pituitary adenoma. Abdominal contrast-enhanced computed tomography (CT) revealed a 6.5 cm heterogeneous right adrenal mass with mildly contrast enhancement. The tumor was found during a routine physical check-up at a local hospital 16 months ago; however, the patient did not have any symptoms and did not seek further medical attention at that time. Laparoscopic resection of the right adrenal tumor led to a rapid remission of Cushing's syndrome. Based on pathological findings and the presence of normal catecholamine metabolites in her serum and urine, the patient was diagnosed with noncatecholamine-secreting pheochromocytoma. Immunohistochemical staining of the adrenal tumor revealed positive staining for CRH and negative staining for ACTH. CONCLUSIONS: This is an extremely rare case of ectopic CRH syndrome caused by an adrenal noncatecholamine-secreting pheochromocytoma. Both ectopic ACTH syndrome and ectopic CRH syndrome should be considered in patients presenting with ACTH-dependent Cushing's syndrome caused by extrapituitary diseases.

[Clinical analysis of 6 cases of Bartter syndrome].

OBJECTIVE: To summarize the clinical characteristics of Bartter syndrome and investigate its pathogenesis. METHODS: The clinical data of 6 cases of Bartter syndrome at our hospital from November 2006 to May 2010 were analyzed retrospectively. RESULTS: The onset age of Bartter syndrome was 13-35 years old. The main symptoms included weakness (6/6), paralysis (1/6), numbness (5/6) and tetany (4/6). All patients had normal blood pressure. The biochemical tests showed persistent hypokalemia, metabolic alkalosis (6/6) and hyperreninemia. The pathological examination of deltoid muscle biopsy showed the swelling, degeneration and necrosis of myocytes and the deposition of immunocomplex in myolemma. And the pathological examination of renal biopsy showed the hyperplasia of juxtaglomerular apparatus (5/6) and the deposition of immunocomplex. All symptoms were relieved after a therapy of potassium supplementation or a combination of indomethacin, spironolactone and immunosuppressant. CONCLUSION: When such clinical features as weakness, paralysis, tetany, hypokalemic alkalosis and normotension are encountered, Bartter syndrome should be suspected. Serum electrolytes, blood gas analysis and activation of the renin-angiotensin-aldosterone system should be examined for a definite diagnosis. The treatment of choice includes potassium and magnesium supplementation or in combination with prostaglandin synthetase inhibitor, aldosterone antagonist and immunosuppressant. Immunologic mechanism may participate in the course of Bartter syndrome.