A case of adenocarcinoma arising in an ileal diverticulum resected by laparoscopic surgery

Adenocarcinoma arising in an ileal diverticulum are very rare. A 66-year-old man was recognized to have high serum CEA level and periappendiceal polycystic tumor in CT findings. Colonoscopy showed no abnormality in the ileocecal mucosa. However, the patient was suspected of appendiceal adenocarcinoma by PET/CT, which revealed FDG uptake with SUVmax of 3.9 in the tumor, and underwent radial surgery by single-incision laparoscopic surgery. Intraoperative findings showed the mass in the mesenterium of the terminal ileum but not the abnormality of the appendix. The resected specimen revealed a cystic tumor of 45 mm on the back side of the intestinal tract. Pathological findings showed that the tumor lesion mainly consisted of mucinous adenocarcinoma was developing from the base of the ileal diverticula. The postoperative process was going well, and the patient left the hospital 14 days after the operation. The recurrence has not been evident 10 months after the operation.