Combined tumor consisting of non-functioning adrenocortical adenoma and pheochromocytoma in the same gland.

A 59-year-old woman was admitted to East Tokyo Metropolitan Hospital for further examination of a left adrenal mass. Catecholamine levels in the plasma and urine were within normal limits. Neither (131)I-metaiodobenzylguanidine (MIBG) nor norcholestenol iodomethyl ((131)I) had accumulated in the left adrenal gland. A left adrenalectomy was performed through a retroperitoneal endoscope. Sections showed a tumor consisting of two parts. Histologically one part of the tumor was completely encapsulated, with clear cells comprising a honeycomb-like mass, regarded as adrenocortical adenoma. The other part consisted of rich cytoplasma and these basophilic, hyperchromatic cells included alveolar patterns, resulting in the diagnosis of pheochromocytoma. Thus, an extremely rare case of non-functioning adrenal incidentaloma consisting of an adrenocortical adenoma and a concomitant pheochromocytoma in the same gland is reported here.