Adrenocortical carcinoma is a rare cancer, with a reported incidence of 0.5–2.0 cases per million/population/year. Adult adrenocortical carcinoma has a poor prognosis, underscoring the importance of identifying diagnostic and prognostic markers. A 15-year search of our laboratory database for all cases with a diagnosis of adrenocortical carcinoma was undertaken. A total of 8 cases were identified, including one adrenal sarcomatoid carcinoma. We examined the histopathological features of the tumors, specifically assessing for the presence of cellular necrosis, mitotic activity, pleomorphism and vascular invasion. The integrity of the reticulin framework was also examined. Immunohistochemical evaluation of the expression of p53, (β-catenin, and Ki67 as a marker of proliferative activity was undertaken. p53 was positive if greater than 10% of cells showed nuclear staining. Necrosis was noted in six of the eight tumors, while vascular invasion was observed in five. Seven tumors had an altered reticulin fiber network. The number of tumors with a high proliferative activity, defined as a Ki67 level of greater than 40%, was six. Five of the tumors were p53 positive, while four stained positive for (β-catenin. In summary, we present eight cases of adrenocortical carcinoma with an examination of histological and immunohistochemical features of diagnostic and prognostic value.