Protruded variants in solitary ulcer syndrome of the rectum.

A review of 21 patients with protruded lesions in solitary ulcer syndrome of the rectum confirmed by resection is presented. Symptoms were usually the passage of blood and mucus per rectum, alteration of bowel habit, anorectal pain and rectal prolapse. Solitary or multiple polypoid lesions were found within 15 cm of the anal margin and were usually sited anteriorly. Fifteen of the patients were men and 8 were women with a mean age of 37.1 years. The diagnosis was made on the basis of histopathology; 1) fibrous obliteration of muscle fibers, 2) reactive hyperplasia of the mucous membrane with villous configuration or mild pseudoinvasion. These changes have been observed in complete rectal prolapse, colonic intussusception, and localized colitis cystica profunda, suggesting a common pathogenesis. The histological findings were almost the same as in the ulcerative lesions of this syndrome except for remarkable regenerative hyperplastic changes such as a relatively high incidence of mucous cell proliferation, dilatation of glands and serrate change in the cases showing protrusion. In the pathogenesis, the occult mucosal prolapse in association with excessive straining may be of particular importance, so that the lesions might be termed mucosal prolapse syndrome of the rectum.