Incidental finding of pseudomyxoma peritonei at primary cesarean section.

Primary appendiceal carcinoma is extremely rare and is found in approximately 1% of appendectomy specimens. When cancer is present, the most frequent histology is mucinous adenocarcinoma. Neoplasms of the appendix that secrete mucin such as adenocarcinoma may rupture, leading to intraperitoneal seeding of the peritoneum and producing the clinical picture of pseudomyxoma peritonei (PMP).