A CASE OF RECTAL DIVERTICULUM PRESENTED WITH SEVERE STENOSIS OF THE RECTUM

Abstract

We report a case of rectal diverticulum resulted in severe stenosis of the rectum, in which the differntial diagnosis from a malignant tumor was difficult. A 34-year-old man complainted of anal pain and dyschezia. Enema and endoscopic examination of the colon revealed severe stenosis of the rectum. Conservative treatments did not yield a remission, the disease progressed, and a possible malignancy was suspected, hence, laparotomy was performed. Perirectal tissues showed stone-like consistency because of chronic inflammatory change, for which tissue biopsy could not be applied. From some findings during surgery, the possible malignancy could not be denied, abdominoperineal excision of rectum being performed. Pathological examiantion revealed a structure of diverticulum in the rectal muscularis and a severe inflammatory feature ranging to the tunica externa. The lesion was diagnosed as inflammatory rectal stenosis resulted from expanded diverticulitis to the surrouding tunica tissues of the rectum. Compared to other colic diverticulums, rectal one more rarely occurs and 7 cases were reported in Japan. Like the others rectal diverticulum is asymptomatic as far as it has no complication. Howerver, as shown in this case, differential diagnosis from a malignancy may be difficult when an inflammatory tumor is formed in the surrounding tissues and/or stenosis is caused by the tumor.