Vesicocolic fistula due to "collision" between adenocarcinoma of the colon and transitional cell carcinoma of the urinary bladder.

A patient with sigmoidocystic fistula due to "collision" between mucoid adenocarcinoma of the colon and transitional cell carcinoma of the urinary bladder is presented. A wide resection of the colonic tumor, along with the involved bladder segment, and a decompressive colostomy with bladder drainage by catheter, were performed. The clinical symptoms, diagnostic procedures, operative treatment, and prognosis are discussed. Although fistular formation is an indication of advanced carcinoma, wide resection of the tumor and the associated fistular along with the node-bearing area will result in a reasonable percentage of 5-year survivals.