Microscopical cancer of the stomach--a study on histogenesis of gastric carcinoma.

In order to elucidate the histogenesis of gastric cancer preceded by "chronic gastritis", 67 foci (58 cases) of minute cancer less than 5 mn in largest diameter were examined histologically. The results obtained were as follows: (1) Except in two cases, all minute cancerous foci were found unexpectedly in the mucosa of the antrum or of the angulus having peptic ulcer or gastric cancer. They were more frequent in the lesser curvature than in other parts of the stomach. (2) Histologically, 18 foci were found in an area close to the main lesion, while 40 were far from the lesion. Seven foci were detected in the mucosa adjacent to ulcer scars. (3) In retrospective macroscopical examinations, 41 foci showed minimal erosion or tiny depressions on the affected mucosa, while in the other 26 no recognizable changes were observable. (4) Histologically, the gastric mucosa outside the cancer lesions was more or less atrophic with or without intestinal metaplasia. (5) Regardless of histological types, all the minute cancers were found in the transitional zone between foveolar epithelium and pyloric glands corresponding to "generative cell layer" in autoradiographic studies. (6) Poorly differentiated adenocarcinomas containing signet-ring cells occurred most often in combination with no or slight intestinal metaplasia of the mucosa, while well-differentiated adenocarcinomas were always found in ventricles with severe intestinal metaplasia.