A 64-year-old female was admitted to our clinic with a 9-cm-sized adrenal mass. The patient's main symptom was hirsutism, which included thinning scalp hair and excessive hair growth over her torso and arms. Upon investigation, elevated values of testosterone, androsterone D4, and DHEA-S were found. Contrast-enhanced abdominal CT and MRI scans revealed a heterogenous large mass (diameter 9 × 8.5 cm) with focal calcifications, necrotic areas, and a clear distinction from the adjacent structures. The patient underwent a right adrenalectomy. The histological examination of the tumor revealed a borderline adrenocortical oncocytoma. The patient had an uncomplicated postoperative course and was discharged on postoperative day 8. Similar cases reported in the literature are also being reviewed in this case report.