Presentation
Left flank pain and hematuria.
Patient Data
A "ball type" mass measuring 70x72x76 mm is seen in the left kidney. On the contrast phase, most of the mass enhances fairly homogeneously but the central part of the mass has a stellate hypodense structure which does not enhance suggestive of a scar lesion. On sagittal reconstruction can see a "spoke wheel" pattern.
There are no lymph nodes, no renal vein thrombosis.
The patient underwent a left nephrectomy.
The samples demonstrated tumor cells having abundant eosinophilic cytoplasm, and small, round nuclei. The tumor cells arranged in nests. There is no significant atypia, mitotic activity or necrosis. These histopathology features are compatible with renal oncocytoma.
Case Discussion
CT findings are suggestive of renal oncocytoma but should prompt consideration of the differential diagnosis of chromophobe RCC. These two entities are difficult to distinguish on imaging.
Histopathology confirmed the diagnosis of renal oncocytoma.