Early detection of nonpolypoid cancers in the rectal remnant in patients with familial adenomatous polyposis/Gardner's syndrome.

Abstract

Invasive cancer occurs in the rectal remnant of patients with familial adenomatous polyposis (FAP). A long term surveillance proctoscopy program was performed on 25 patients with an established diagnosis of FAP or Gardner's syndrome. The surveillance revealed small nonpolypoid cancer of the rectal remnant in two patients. One cancer, which measured 5 mm, was restricted to the mucosa, whereas the other, measuring 10 mm at its greatest dimension had invaded the submucosa. On proctoscopy, both the lesions were characterized by a reddish depression, surrounded by marginal elevations. Both of these cancers were composed of well differentiated adenocarcinoma without any adenomatous component. The authors' experience suggests that nonpolypoid cancers do exist in FAP/Gardner's syndrome and that careful follow-up seems necessary in patients with a diagnosis, especially in consideration of the possible development of nonpolypoid lesions.