[Morphology and differential diagnosis of oncocytic kidney tumors]

5 oncocytomas and 3 oncocytic carcinomas were studied morphologically, morphometrically, cytophotometrically, histochemically and ultrastructurally. Oncocytic carcinoma is characterized by the presence of necrotic foci, pronounced cell and nuclear polymorphism, invasive growth. Significantly higher degree of the nucleus size variability is found in the oncocytic carcinoma (as compared to oncocytoma). Anomalies of DNA content in the form of aneuploidy and polyploidy are found cytophotometrically in all oncocytic carcinomas but in 2 out of 5 cases oncocytomas only.