Pheochromocytoma and Adrenocortical Adenoma in the Same Gland

A right adrenal tumor was found incidentally during abdominal computed tomography exam in a 51-year-old female patient, who had had diabetes and hypertension for more than 10 years. The computed tomography scan was arranged for possible pancreatic lesion by a neurologist. Norepinephrine level was high in the plasma and urine. Vanillylmandelic acid level was elevated in the urine. Diurnal cortisol rhythm, plasma adrenocorticotropic hormone and urine free cortisol were all normal, but the plasma cortisol concentration could not be suppressed after a standard low-dose dexamethasone suppression test. Therefore, adrenal cortical adenoma with subclinical Cushing's syndrome was highly suspected; however, further imaging studies, including magnetic resonance image and 131I-6β-iodomethylnorcholesterol adrenal scintigraphy failed to discriminate an additional tumor. After right adrenalectomy, a small adrenal cortical adenoma and a large pheochromocytoma were noted. This is an extremely rare case of an adrenal incidentaloma consisting of both medullary and cortical tumors in the same gland.