Computed tomography of renal oncocytoma.

Six patients with small solid renal tumors were evaluated by computed tomography (CT). Two patients had renal oncocytomas, three had small renal cell adenocarcinomas, and one had separate foci of each of these tumors in the same kidney. We describe several features that may alert the clinician to the possible presence of oncocytoma. We found, however, that unless the dense central scar that can be seen in larger oncocytomas is visualized on CT (as was the case in one of our patients), differentiation between oncocytomas and renal cell carcinomas by CT is not possible.