[A case of renal cell carcinoma metastasizing to the contralateral kidney and renal pelvis].

Extremely rarely renal cell carcinoma metastasizes to the contralateral renal pelvis or ureter. A 42-year-old man had undergone left radical nephrectomy for renal cell carcinoma (pT1b, grade 2) in March, 2000. Fifteen months later, he complained of macroscopic hematuria. Computed tomographic scanning and retrograde pyelography showed a right renal pelvic tumor. Enucleation of pelvic tumor was performed and a parenchyma mass incidentally identified in the right kidney was also resected. Histopathological examination of each tumor revealed renal cell carcinoma identical to the primary tumors in the left kidney suggesting metastasis to renal pelvis and de novo tumor or metastasis in the right kidney.