Oncocytic neoplasms of adrenal cortex are extremely rare and usually discovered incidentally.

We present 11 cases included in a series of 1100 operations for adrenal tumors. There were 6 female and 5 male patients , 30 to 71 years old, with 7 left adrenal tumors and 4 right adrenal tumors. The size of tumors ranged from 6,5 to 9 cm. Two patients had autonomous cortisol secretion and one autonomous secretion of cortisol and aldosterone. In one patient with MEN I syndrome and history of pancreatectomy , splenectomy and excision of pituitary adenoma , a bilateral adrenalectomy was performed because of bilateral adrenal hyperplasia and overt Cushing syndrome. The patient had oncocytic neoplasm in the left adrenal gland and metastasis from the neuroendocrine tumor in the other gland with oncocytic conversion.

There were 3 open and 8 laparoscopic adrenalectomies . The histopathology revealed 4 benign oncocytomas and 7 oncocytic neoplasms of uncertain malignant potential . The Ki-67 ranged from 1% to 10%. In one patient en bloc resection of the tumor with the kidney was performed because of possible vascular invasion of the renal hilum. The final histologic report showed a benign oncocytoma. The postoperative course was uneventful. There was neither mortality nor recurrence in a follow up of 10 years.

Oncocytic adrenocortical neoplasm is a rare histologic variant with more indolent outcome in comparison with conventional adrenocortical carcinoma despite the large size and the suspicious characteristics in the imaging studies as well as suspicious appearance in the operative field .