One of the problems in managing adrenocortical tumors is the ability to distinguish between benign and malignant tumors, while needle biopsy is unable to distinguish between the two situations. Therefore, when imaging tests demonstrate a suspected malignant adrenal tumor, surgical excision of the tumor is needed. Usually, the histological WIESS criteria are used in order to determine malignancy. However, there are cases when adrenal tumors were defined by WIESS criteria as benign but metastasized later. Moreover, there is no reliable test than can determine prognosis. KI-67 labeling index is a proliferation biomarker which is used to tell more about the malignant potential and prognosis of adrenal carcinoma.