Abstract
Clinical and Pathological studies were performed on 34 lesions of minute gastric cancer (less than 5 mm in the longest diameter) and 65 lesions of small gastric cancers (from 6 mm to 10 mm in the longest diameter). Macroscopically the depressed lesions were classified into 4 types, which were minute depression, malignant erosion, intermediate and IIc type. The elevated lesions were classified into 3 types, which were central depression, smooth surface and irregular surface type. All histological types of adenocarcinoma could be recognized in every depressed types and there were no particular histological differences in the surrounding mucosa among the four depressed types. Depressed minute gastric cancers showed either minute depression type or malignant erosion type and they were carcinomas of intramucosal cancerous invasion. Depressed small gastric cancers showed one of the three types, that is malignant erosion or intermediate or IIc type and some of them revealed cancerous invasion into the submucosal layer. Histologically all the elevated lesions were tubular adenocarcinomas of intramucosal cancerous invasion. Macroscopic type of elevated minute gastric cancers was central depression or smooth surface type. Intestinal metaplasia and atrophic gastritis existed in every mucosa sur-rounding the elevated lesions. Pressure by the cancer cells in the deeper part of the mucosal layer and proliferation of gastric glands and foveolar epithelium were thought to contribute much to the component of the elevation surrounding depressed lesion which was noticed in malignant erosion and intermediate type.
