Gastric cancer preceded by severe dysplasia.

For elucidation of histogenesis of gastric cancer derived from relatively flat mucosa, 77 cases of surgically resected stomachs with lesions of severe dysplasia in cancerous mucosae or with cancerous changes in severely dysplastic mucosae were detected out of 380 recently examined cases of early gastric cancer. Several examples of early gastric cancer of the superficial type, showing histological changes indicating that they had developed on the preexisted dysplastic mucosal lesions, have been presented, together with the background data. The frequency for detecting such changes was higher in the slightly elevated lesions than in the depressed or eroded ones.