膀胱癌是指发生在膀胱黏膜上皮的恶性肿瘤，是泌尿系统最常见的肿瘤。膀胱癌按浸润深度可分为非肌层浸润性膀胱癌和肌层浸润性膀胱癌，非肌层浸润性膀胱癌患者多采用经尿道膀胱肿瘤电切术，术后辅以膀胱内灌注治疗，预防肿瘤的复发；肌层浸润性膀胱癌由于浸润深度深，易发生转移，故多采用膀胱全切［1］。膀胱全切后肠代膀胱被认为是膀胱全切后下尿路重建的金标准［2］，但是由于肠代膀胱后尿液经由肠管排泄，肠管不能完全替代膀胱，可产生电解质紊乱、尿路感染、积水等诸多并发症［3］，其中已经证实肠代膀胱后可能再发生肿瘤，其发生概率虽低但已成为不争的事实，本文介绍1例北京大学第三医院Studer肠代膀胱内新发肠源性腺癌的病例。

Intestinal primary intestine-derived adenocarcinoma of the bladder substituted by the intestine is a very rare long-term complication after complete urethral reconstruction of the bladder. The probability of its occurrence is low. However, in recent years, it has been proved to be objective, but there is rare literature about its diagnosis and treatment methods. This article describes a case of cystectomy and Studer ileal conduit in Peking University Third Hospital due to bladder cancer. After 9 years, he was discovered with a primary intestinal-derived adenocarcinoma in the bladder substitutes by the intestine. A male patient, 64 years old, with persistent abdominal pain in the lower abdomen for two weeks. There was carrion-like material in the urine, no gross hematuria, no urinary frequency, urgency, dysuria, and no abnormalities in the examination. Urinary CT showed intestinal metaplasia in the bladder. There was 5.7 cm×2.4 cm×4.8 cm irregular tissue shadow, and ureteroscopy found, on the right side, the bladder tumor whose diameter was 4-5 cm. We performed open lumpectomy and repaired the bladder, and postoperative pathology showed middle-high differentiated adenocarcinoma. The patient recovered well after the surgery. This article reviewed the similar intestinal primary intestinederived adenocarcinoma of the bladder substituted by the intestine and found that it had the highest incidence in the elderly male population. The pathogenetic factor was most closely related to the smoking. If the patients developed hematuria, carrion-like substances in the urine, and bladder irritation, the possibility of tumor development should be suspected. Then the patients should promptly take the tests, such as urine exfoliation cytology, urine FISH, urinary system B-ultrasound, cystoscopy, etc. The microscope was the most direct observation of the lesion site examination. If the pathological tumor occurred ,and then the tumor should be immediately removed, and a new urinary diversion was needed to avoid further progress of the tumor. And postoperative smoking was strictly prohibited, also the patients should strictly control their eating habits and regularly adhere to the follow-up at least 4 years or more, but the lifelong follow-up and review was a must. The mechanism of intestinal primary intestine-derived adenocarcinoma of the bladder substituted by the intestine is still unclear. Studies suggest that it may be related to N-nitroso compounds, smoking, and postoperative inflammatory reactions.