Synchronous occurrence of appendiceal mucinous cystadenoma, with colon adenocarcinoma and tubulovillous rectal adenoma: Management and review of the literature.

Appendiceal mucocele (AM) is a rare clinical entity comprising 8% of all appendiceal tumors, and it is seen in 0.2-0.3% of all appendectomy specimens. Apart from sporadic cases, there are no enough published data about the incidence of synchronous appendiceal tumors in patients with colorectal cancer. We describe a very rare case of synchronous occurrence of AM, colon adenocarcinoma, and tubulovillous adenoma of the rectum and review the relevant literature. We conclude that thorough preoperative and perioperative evaluations are mandatory in patients undergoing surgery for colorectal cancer to exclude a synchronous colon or an appendiceal primary tumor. Larger prospective studies are necessary to accurately determine the incidence of synchronous appendiceal tumors and colorectal cancer.