This is a case report of a 40-year-old man with an adrenal mass that was found incidentally on routine check-up examination. MRI showed a 30 × 51 × 57 mm cystic-semisolid heterogeneous mass; hormonal functions were within normal limits. Operative removal was planned because of the large size of the mass. Histopathological and immunohistochemical findings were consistent with adenomatoid tumour. The patient was disease-free at 1 year follow-up. We present this case with its radiological and histological characteristics under the review of the literature.