A case of obstructive colitis due to rectal cancer with penetration to the mesenterium

Abstract

A 77-year-old man was admitted to our hospital because of heart failure and anemia. On admission, he had no symptoms of intestinal obstruction. Pre-colonoscopy treatment (laxative administration) induced abdominal pain and melena. Colonoscopy revealed a circumferential tumor in the lower rectum. The following day he developed massive melena with hemorrhagic shock, for which emergency surgery was performed. At laparotomy, purulent ascites and a fecal odor were noted. A tumor was present in the lower rectum, the proximal portion of which was markedly distended, and its mesenterium was grayish-white, and was discharging pus. Intestinal obstruction due to rectal cancer had caused rupture and perforation of the sigmoid colon into the mesenterium, and the perforated portion had ruptured, resulting in peritonitis. Therefore, we performed abdominoperineal resection of the rectum. The resected specimen contained a circumferential type-2 tumor of the lower rectum, and penetration with an opening of 7 × 5—cm into the mesenterium, which contained free vessels. From the presence of a large amount of blood clot in the rectum proximal to the tumor and the finding of free vessels in the mesenterium, we speculate that blood vessels in the perforated mesenterium were the source of bleeding.