Radionuclide imaging and computed tomography in renal oncocytoma.

Renal oncocytoma is an apparently benign neoplasm that is being reported with increasing frequency. It is important to differentiate it from renal-cell carcinoma prior to surgery. Angiographic, CT, and ultrasound studies may suggest the diagnosis but are not pathognomonic. In 4 cases, 99mTc-glucoheptonate imaging of the renal tubules was performed; one patient was also scanned in 131I-orthoidohippurate. There was no evidence of radionuclide uptake by the tumor. Reasons for the lack of success in differentiating renal oncocytoma from renal-cell carcinoma are discussed.