Multicentric renal oncocytoma.

Renal cell oncocytomas are benign tumors of tubular epithelial origin. They usually occur as single nodules and may be confused clinically with renal cell carcinoma. We report an unusual case of multiple, discrete renal cell oncocytomas. The characteristic gross and light microscopic, and ultrastructural features are described. The potential of multicentricity is confirmed and its implications for therapy are discussed.