Oncocytic adrenal adenoma: Diagnostic challenge of an incidentaloma; a case report

Adrenal oncocytic neoplasms (AONs) are rare non-functioning adrenal tumors with difficult preoperative diagnosis. We report a 40-year-old man with an 11 cm adrenal mass, negative hormonal workup, and imaging findings. The patient underwent open adrenalectomy. Histopathology showed oncocytic adenoma with borderline/uncertain malignant potential per Lin-Weiss-Bisceglia criteria (size >10 cm, necrosis). Postoperative course was uneventful, with no recurrence at 18 months. AONs should be considered in large adrenal incidentalomas; complete resection is essential for diagnosis, risk stratification, and follow-up.