Appendix carcinoma invading the urinary bladder.

We report a case of an appendix carcinoma invading the urinary bladder. In contrast to other bowel tumors invading the bladder, history and symptoms were consistent with a primary bladder tumor. This is due to the unique anatomical position of the appendix where the tumor did not hinder passage of bowel contents or cause melena. Findings on physical examination as well as diagnostic imaging and transurethral resection were inconclusive. Consideration of local progression of an appendix carcinoma is an important differential diagnosis. In contrast to other vesical or extravesical T4 tumors, the appendix carcinoma offers a good chance for resection en bloc by right-sided hemicolectomy and partial cystectomy.