[Initial changes in the development of gastric cancer].

Among 123 cases of surgically resected stomachs bearing minute cancerous foci, which comprised 9.5% of all the early gastric cancers obtained, six cancerous foci with either intestinal type of diffuse-type histology showing the earliest changes of development were selected and the macroscopic and histological features of the foci were presented. Foci of the former type were found in the deepest layer of the gastric foveolae in severely metaplastic mucosa in a budding-like growth pattern and tended to enlarge the area toward the surface of the mucosa, which resulted in tiny focal depressions of the affected mucosa. On the other hand, lesions of the latter type were found in the neck zone of the mucosa with little or no intestinal metaplasia and spread laterally into the surrounding mucosa by infiltrative growth as groups of signet-ring type cancer cells, which resulted in cancerous erosion of the affected mucosa.