Oncocytic adrenocortical carcinoma:a clinicopathological analysis

Objective To report two cases of oncocytic adrenocortical carcinoma and to investigate the clinicopathological characteristics. Methods Histological observation,immunohistochemical staining and ultrastructural studies were conducted and related literatures were reviewed. Results Oncocytic adrenocortical carcinoma mainly occurred in young or middle-aged adults and showed similar sex ratio.The cut surfaces were white and yellow with necrosis.The tumor cells were exclusively oncocytic with a diffuse arrangement.Nuclear atypia was identified.Tumor cells were positive or negative for inhibin-α and immunoreactivity for Melan-A and Syn were strongly positive.Both tumors had low proliferative indices of less than 5%.Ultrastructural studies showed that tumor cells were filled with mitochondria. Conclusion Oncocytic adrenocortical carcinoma is extremely uncommon,whose definite diagnosis should be based on the histopathological and immunohistochemical features to exclude other tumors,and it might be a low-grade malignancy.