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.