Appendiceal cancer is extremely rare. We experienced two cases of appendiceal cancer which were detected with clinical manifestations mimicking acute appendicitis.
Case 1: A 70-year-old woman, Barium enema study demonstrated a deformity of the appendix. Abdominal CT scan revealed a large amount of ascites in the entire abdomen. At laparotomy, the appendix was perforated at the tip and the pelvic cavity was occupied with mucinous fluid. Appendectomy, omentectomy and removal of mucinous fluid were performed. Microscopic examination of the appendix showed pseudomyxoma peritonaei causing mucinous cystadenocarcinoma.
Case 2: A 67-year-old man, Barium enema study did not visualize the appendix but showed compression of the cecal wall. Abdominal CT scan revealed a pericecal mass. At laparotomy, a periileocecal abscess was found and right hemicolectomy was performed. Macroscopic examination of the resected specimen showed a villous tumor at the orifice of the appendix. Microscopic examination of the appendix showed well differentiated adenocarcinoma. This rare tumor should be kept in mind as a probable differential diagnosis for acute appendicitis.