Multifocal early gastric cancer: morphology and histogenesis.

69 foci from 27 multifocal EGC are compared morphologically with 90 solitary EGC. In the multifocal group there was a preponderance of gross types IIa and IIb, Small and Minute carcinomas, an intramucosal growth pattern and a well differentiated intestinal histotype. Although the differences in gross type and tumor size are related in some measure to the stage of neoplastic growth at the time of diagnosis, the higher frequency of well differentiated intestinal carcinomas in multifocal EGC probably reflects a different histogenesis. This hypothesis seems to be borne out by the greater extent of intestinal metaplasia and the larger number of dysplastic foci detectable in the surrounding gastric mucosa.