[Diagnosis of the upper urothelial tumor using a rigid ureteroscope]

We preoperatively diagnosed four cases suspected as malignant urothelial tumor of upper urinary tract using a rigid ureteroscope. In three cases of ureter tumor, biopsy was successful and showed low grade malignancy. Nephroureterectomy was performed in two cases with upper ureteral tumor. The tumor was fulgurated ureteroscopically in a case of lower ureteral tumor. In one case of renal pelvic tumor, biopsy was unsuccessful though the tumor was observed as a papillary configuration. Successively, biopsy using a flexible ureteroscope was performed and the tumor was treated by fulguration. Ureteroscopy is very useful for preoperative diagnosis of ureteral tumor and selection of treatment.