ADRENOCORTICOTROPIC HORMONE-SECRETING PHEOCHROMOCYTOMAS - THE EXCEPTION TO THE RULE

Background. Operative management of pheochromocytomas dictates resection of the involved adrenal and exploration-resection of the contralateral gland if enlarged. We describe an exception to this rule. Methods. We report the largest series of patients with adrenocorticotropic hormone (ACTH)-secreting pheochromocytomas and review the world literature. Results. Four patients presented with findings of adrenocorticoid and catecholamine excess, as well as elevated levels of plasma ACTH, urinary metanephrines, and urinary free cortisol. Abdominal computed tomography scans revealed bilateral adrenal hyperplasia, and magnetic resonance imaging scans showed a unilateral adrenal mass with a bright T2 signal suggesting a pheochromocytoma. Two patients underwent adrenal venous sampling localizing ACTH secretion to the pheochromocytoma. All underwent unilateral adrenalectomy for a benign tumor without morbidity or death, leaving the contralateral hyperplastic adrenal in situ. After operation all patients experienced normalization of their levels of plasma ACTH, urinary metanephrines, and urinary free cortisol with resolution of symptoms. Combining our series with previously reported cases of ACTH-secreting pheochromocytomas, almost all are benign (20 of 21) in contrast to most ACTH-secreting tumors. Conclusions. ACTH-secreting pheochromocytomas are the exception to the rule; unilateral adrenalectomy is curative and the contralateral hyperplastic adrenal can be preserved. This approach results in resolution of both syndromes of hormone excess and preserves long-term adrenal function.