A, Classic appearance of oncocytoma with small solid nests with myxoid or hyalinized background. B, Tubular architecture of oncocytoma with hemorrhage. C, Classic cytology of oncocytoma with abundant eosinophilic cytoplasm; indistinct cell borders; small, uniform nuclei; and prominent nucleoli. D, A cluster of degenerative-type atypia seen in oncocytoma. E, Scattered cytokeratin 7 immunoreactivity in oncocytoma. F, Biopsy of an oncocytic renal neoplasm consistent with oncocytoma (hematoxylin-eosin, original magnifications ×100 [A, B, and F], × 600 [C], and ×400 [D]; original magnification ×400 [E]).