Gastric pseudopolyposis: a new clinical manifestation of type A gastritis.

Three cases of type A gastritis associated with multiple polypoid lesions of the body of the stomach are presented. The endoscopic congo-red test showed the red to black color changes of the sprayed congo-red only on the top of the polypoid lesions. The endoscopic methylene-blue test revealed no dye absorption on the antral mucosa or on the top of the polypoid lesions, while the dye was absorbed on the flat mucosa surrounding the top of the polypoid lesions. Histological examinations revealed well-preserved oxyntic glands on the top of the polypoid lesions. The flat mucosa showed marked atrophy or intestinal metaplasia. There have been several reports of experimental models of type A gastritis, where chief and parietal cells decreased in considerable number. These findings and the experimental models suggest that the polypoid lesions resulted from atrophic changes of type A gastritis. The top of the polypoid lesions is the residual oxyntic glands. The lesions, therefore, should be called "gastric pseudopolyposis." The spontaneous disappearance of the polypoid lesions seen in one case is thought to be a result of a further progression of the atrophic gastritis. A pronounced G-cell increase was noted in the antrum and lower body of the stomach. This is considered a secondary phenomenon following the marked reduction of acid secretion.