[Adrenocortical tumors with oncocytic cells: benign or malignant?]

Adrenocortical tumor with oncocytic cells are exceptional. They are composed exclusively or almost exclusively of oncocytic cells, which are large cells with eosinophilic granulations, corresponding to numerous mitochondria in electronic microscopic examination. This tumor is usually non-functional and benign, and has to be differentiated from the adrenocortical carcinoma.