ACTH-Producing Pheochromocytoma: A Rare Cause of Ectopic Cushing’s Syndrome

Presentation Number: MON 420
Date of Presentation: April 3rd, 2017

Basak Bolayir1, Damla Okay1, Mujde Akturk*1, Murat Akin1, Aylar Poyraz1, A.Tuncer Sel1, Banu Yilmaz2, Fusun Toruner1 and Alev Altinova1
1Gazi University Faculty of Medicine, Ankara, Turkey, 2Yuksek Ihtisas University, Ankara, Turkey

Abstract

Background: Cushing’s syndrome is a rare disorder and majority of cases result from ACTH-secreting pituitary adenomas. Ectopic ACTH production accounts for approximately 10% of the ACTH-dependent causes. Pheochromocytomas rarely co-secrete catecholamines and ACTH and cause severe disease manifestations resulting from both cortisol and cathecholamine excess. Here, we present an ectopic ACTH syndrome associated with pheochromocytoma.

Clinical case: A 55-year old man was referred to our Endocrinology department with the diagnosis of adrenal mass, discovered during imaging evaluation for suspected nephrolithiasis. He had 3-year history of hypertension and diabetes mellitus. He had classical clinical signs of Cushing’s syndrome. At referral, he was treated with insulin and multiple antihypertensive agents. He was recently diagnosed with atrioventricular nodal reentrant tachycardia. He had severe hypokalemia, elevated urinary cortisol and salivary cortisol, abnormal dexamethasone overnight supression test and very high ACTH levels. His urinary catecholamine metabolites were also elevated. Abdomen CT showed 3.0 cm left adrenal mass with high precontrast density (31HU) and low wash-out value (26%). Pituitary MRI was normal. Metyrapone treatment was initiated to control hypercortisolism preoperatively. Prophylactic anticoagulation was initiated. Alpha-blocker therapy was ordered to control blood pressure and to prevent an intraoperative hypertensive crisis. A left adrenalectomy was performed. Histopathological examination revealed pheochromocytoma without necrosis, atypic mitoses, extra-adrenal extension and vascular invasion. Additional immunohistochemical staining for ACTH was positive. The patient recovered without any complication after surgery. Hydrocortisone was started because of his low cortisol levels. Six weeks after operation, ACTH level and urinary cortisol and catecholamine metabolites were within normal ranges.

Discussion: Pheochromocytoma as a source of ectopic ACTH syndrome should be considered in patients with clinical manifestations of Cushing’s syndrome and adrenal mass.

 

Nothing to Disclose: BB, DO, MA, MA, AP, ATS, BY, FT, AA