Functional adrenocortical oncocytoma: A case report of rare neoplasm of uncertain malignant potential

Adrenocortical oncocytoma is a rare adrenal neoplasm with only 25 cases having been reported in the English medical literature, of which only seven were functional tumors. Since these adrenal tumors are usually nonfunctional, they are mostly incidentally detected, and most of them are benign. Herein, we report on a rare case of a functional adrenocortical oncocytoma of an uncertain malignant potential and this tumor was located in the left adrenal gland in a 59-year-old woman who presented with hypertension. The tumor size was large with foci of necrosis in the cut surface and it exclusively had oncocytic histologic features.