Diminutive colonic polyps: an indication for colonoscopy.

A prospective study investigated the significance of solitary diminutive colonic polyps discovered during screening flexible sigmoidoscopy. Eighty-two patients with a solitary diminutive polyp (less than or equal to 5 mm) underwent colonoscopy after cold biopsy of the index polyp. Of the patients with adenomatous index polyps, 42.5 percent had proximal neoplastic polyps. Of the patients with hyperplastic index polyps, proximal neoplastic polyps were found in 38.9 percent. These data suggest that diminutive polyps identified during flexible sigmoidoscopy, whether adenomatous or hyperplastic, place the patient in the intermediate risk group for colorectal neoplasia. We recommend that any patient with polyps seen during screening sigmoidoscopy, regardless of histopathology, should undergo colonoscopy.