Renal oncocytoma with bilateral synchronous renal cell carcinoma in a patient undergoing long-term hemodialysis.

We report a case of bilateral synchronous renal cell carcinoma and renal oncocytoma in a 56-year-old male who had been treated with hemodialysis for 32 years. Because anemia gradually worsened, computed tomography and magnetic resonance imaging were carried out and revealed bilateral renal tumors within acquired cystic disease of the kidney. Bilateral nephrectomy was carried out, and the patient was diagnosed with multiple renal cell carcinomas and a single renal oncocytoma. To our knowledge, this is the first reported case of renal oncocytoma with synchronous renal cell carcinoma in a patient undergoing long-term hemodialysis.