All of the following are associated with pheochromocytoma except: March 2010
Ventricular arrhythmias
Interstitial fibrosis
Hypotension
Ectopic ACTH production
Ans. C: Hypotension Pheochromocytoma is a neuroendocrine tumor of the medulla of the adrenal glands (originating in the chromaffin cells), or extra-adrenal chromaffin tissue that failed to involute after bih and secretes excessive amounts of catecholamines, usually adrenaline (epinephrine) if in the adrenal gland and not extra-adrenal, and noradrenaline (norepinephrine). Extra-adrenal paragangliomas (often described as extra-adrenal pheochromocytomas) are closely related, though less common, tumors that originate in the ganglia of the sympathetic nervous system. Because of excessive catecholamine secretion, pheochromocytomas may precipitate life-threatening hypeension or cardiac arrhythmias. Nonspecific myocardial changes includes focal necrosis, mononuclear infiltrates and interstitial fibrosis. In some cases pheochromocytoma secrete other hormones, such as ACTH and somatostatin.