Hyperplastic polyposis of the large bowel. Three cases and a review of the literature.

Small hyperplastic polyps of the large bowel constitute a frequent non-neoplastic lesion, whereas large or multiple hyperplastic polyps are rare. Here we report three cases of multiple small polyps together with some large hyperplastic ones. Two of the cases had a primary carcinoma in the bowel before onset of the polyps. The neoplastic potential of the hyperplastic polyp is discussed on the basis of the most recent investigations and the three presented cases. The hyperplastic polyp does not seem to be directly involved in the adenoma-carcinoma sequence, but dysplastic changes can be found in large hyperplastic polyps. In cases of multiple hyperplastic polyps a tendency towards a more uniform distribution of the polyps throughout the large bowel is observed. Hyperplastic colonic polyps may exist as a clinical entity, and a definition based on distribution, multiplicity, size, and symptoms is proposed. Patients with multiple or large hyperplastic polyps should have colonoscopy performed at short intervals, with removal of all lesions larger than 5 mm for histologic examination.