Case of vesico-appendiceal fistula secondary to mucinous adenocarcinoma of the appendix.

We present a rare case of vesico-appendiceal fistula secondary to mucinous adenocarcinoma of the appendix. Transurethral biopsy of the bladder revealed a mucinous adenocarcinoma of probable colonic origin. Adenocarcinoma of the appendix that directly invaded the bladder was diagnosed preoperatively by air-contrast barium enema, colonoscopy and magnetic resonance imaging. When one encounters a case of adenocarcinoma of the bladder suspected to be of colonic origin, one should examine the colon and rectum as well as the appendix and cecum.