双侧上尿路同时出现尿路上皮肿瘤是罕见的,在输尿管肿瘤中,新发生率为2～9％;而在肾盂肿瘤中,其发生率为1～1.9％。当上尿路肿瘤伴发膀胱、尿道浸润时,双侧同时出现肿瘤的发生率反而更低。作者报道3例同时出现的双侧肾盂移行细胞癌病例。同时出现双侧上尿路移行细胞癌,使治疗变得非常困难。作者认为如要完成保留肾脏的手术,就必须在术前进行多种检查,深入估价肿瘤的分期和 The simultaneous appearance of urothelial tumors on both upper urinary tracts is rare. In ureteral neoplasms, the new incidence is 2-9%; in renal pelvic tumors, the incidence is 1-1.9%. When upper urinary tract tumors are accompanied by bladder and urethral infiltration, the incidence of bilateral simultaneous tumors is even lower. The authors reported three cases of bilateral renal pelvic transitional cell carcinoma. At the same time, bilateral upper urinary tract transitional cell carcinoma occurs, making treatment very difficult. The author believes that if the operation to preserve the kidneys is to be completed, multiple tests must be performed before surgery to deeply evaluate the staging of the tumor and