Oncocytic adrenocortical carcinoma: a rare adrenal tumor subtype.

Oncocytic tumors arising from the adrenal gland are rare. Oncocytic adrenal neoplasms (OAN) may mimic adrenocortical carcinoma (ACC) at presentation, and can only be definitively diagnosed histologically. Most OANs are benign, and carry a favorable prognosis. We report on an 83-year-old female who, while being investigated for anemia and weight loss, was found to have a 23 cm adrenal mass concerning for ACC. Adrenalectomy and histopathology confirmed a malignant OAN, based on the Lin-Weiss-Bisceglia criteria. We report on the largest non-functional, malignant OAN cited in the literature to date. OAN's, though rare, can be considered in the differential diagnosis of large adrenal tumors.