Background: A 39-year-old female presented with an incidentally discovered left adrenal mass. She denied any history of hypertension, headaches, palpitations, muscle weakness, bruising easily, or fatigue. Physical examination was unremarkable. Investigations: Physical examination, laboratory analyses, CT scan and MRI. Diagnosis: Oncocytic adrenocortical tumor, or adrenal oncocytoma. Management: Adrenalectomy, gross and histopathologic examination, and follow-up radiologic imaging.