[A case of Cushing's syndrome due to adrenal black adenoma]

Functional black adenoma of the adrenal gland is rare, and there are few reports. We report a case of functional black adenoma of the adrenal gland associated with Cushing's syndrome. The case was in a 59-year-old female, whose chief complaints were weight gain and general fatigue for 7 years. Clinical and laboratory findings were characteristic to those of Cushing's syndrome. With computed tomography and ultrasonography, a round tumor about 18 x 12 mm was detected at the left suprarenal region. Left adrenalectomy was done and a black tumor, 5.0 g in weight, was obtained. Most of the adenoma cells contained numerous pigmented granules which were considered as lipofuscin. The patient is alive without any symptoms of Cushing's syndrome 8 months after the operation. The Japanese literature of the functional black adenoma was also reviewed.