MKI67 and adrenal cortex adenoma: Histological examination (Fig. 2 a) and immunohistochemistry also confirmed the diagnosis of benign adrenocortical adenoma with immunohistochemistry positive for inhibin α, melan A, β-captenin (Fig. 2 b-d), SYN (focal), Ki-67 (< 3%), and negative for chromogranin (CgA), cytokeratin (CK), S-100, P53.