A case of adrenocortical adenoma clinically mimicking pheochromocytoma

The coexpression of cortical and medullary features in a single adrenal cortical cell has been recognized, leading to terms such as cortico-medullary cells. Here, we reported a case of adrenocortical adenoma consisting of cortico-medullary cells that clinically mimicked pheochromocytoma. A 52-year-old woman was admitted to our hospital complaining of an 8-month history of paroxysmal palpitation with refractory hypertension. A 24-hour urine study revealed increased norepinephrine and metanephrine levels. Computed tomography of the abdomen revealed a 1.0×0.9-cm mass in the left adrenal gland. The patient subsequently underwent unilateral laparoscopic adrenalectomy for a presumptive pheochromocytoma. Light microscopic findings of the left adrenal mass indicated an adrenocortical adenoma, but electron microscopy identified lipid vacuoles and smooth endoplasmic reticulum, along with dense core neurosecretory granules, so-called cortico-medullary cells. This is the first report of the detection of cortico-medullary cells in adrenocortical adenoma presenting as pheochromocytoma in Korea. (Korean J Med 75:479-483, 2008)