HISTOGENESIS OF HYPERPLASTIC POLYPS OF THE STOMACH IN TERMS OF CELLULAR PROLIFERATION

We investigated the histogenesis of hyperplastic polyps of the stomach , in terms of cellular proliferation, by studying endoscopically remov ed and gastrectomized human gastric polyps either labeled with bromode oxyuridine (BrdU) by in vitro flash labeling techniques or labeled in an isolated organ circulation system, in both of which, perfluorochemi cal artificial blood was employed. Immunohistochemistry with antibodie s against BrdU and proliferating cell nuclear antigen (PCNA) was simul taneously employed. The generative cell zone of pedunculated and semip edunculated polyps was markedly expanded compared with that of the bac kground mucosa, and this change also appeared in sessile polyps, altho ugh to a lesser degree. Enhanced proliferative activity was observed i n both epithelial and stromal cells in areas of erosion. Our results d emonstrate that the initial change in the histogenesis of hyperplastic polyps is an expansion of the generative cell zone, followed by inter stitial edema and stromal cell proliferation, and that erosion can fac ilitate these changes. No correlation was found between the size of th e polyps and the labeling indices. This finding explains, in part, the diversity of chronological changes in the size and shape of hyperplas tic polyps.