Hyperplastic (metaplastic) polyps of the colon. A histologic and histochemical study.

One hundred seventy-three hyperplastic polyps removed from the colon of 146 patients were carefully examined by light microscopy in order to evaluate the histologic variants. Seventy polyps were also studied histochemically in order to assess the mucin distribution. Seven polyps measured greater than 1 cm. The frequency of hyperplastic foci has been assessed in a review of 1000 colonic adenomas, 50 juvenile, 30 inflammatory, and six Peutz-Jeghers polyps. The vast majority of the hyperplastic polyps showed features similar to those of inflammatory and ischemic bowel mucosa, leading to the suggestion of an inflammatory-ischemic origin of the polyps. The frequent finding of dysplastic features within hyperplastic polyps greater than 1 cm suggests that at least the large polyps are dysplasia-prone.