Studies on Histogenesis of the Gastric Carcinoma Using Minute Cancers

Abstract

Summary Histopathologically, we examined 53 lesions, in 13 cases, of minute cancers measuring less than 5 mm in the largest diameter, in order to study the histogenesis of gastric cancer. Forty-four lesions in four cases were undifferentiated adenocarcinoma, and nine lesions in nine cases were differentiated adenocarcinoma. Cancer cells of the undifferentiated type were confined to the lamina propria of the mucosa, especially near the generative cell zone of the neck of the gastric pit, and had a tendency to extend to the surface as the size of the minute cancer increased. The surrounding mucosa was ordinary epithelia of the stomach without intestinal metaplasia. Atrophy of the pseudopyloric and fundic glands was seen at the lesions with inflammatory-cell infiltration. Cancer cells of the differentiated type had a tendency to involve the entire thickness of the mucosa by replacing the epithelia of the gastric pits. The surrounding mucosa was composed of markedly intestinalized epithelia. And the border between the cancer cell and the intestinalized epithelial cell was sharp. Atrophy of the pseudopyloric and pyloric glands was seen at the lesions with inflammatory-cell infiltration. We conclude that both types of carcinomas occur from the generative cell zone of the gastric pit. Cancer cells of the undifferentiated type may originate in the ordinary mucosa of the stomach, penetrate the basement membrane of the epithelia of the gastric pit and appear in the lamina propria. On the other hand, cancer cells of the differentiated type seem to originate in the intestinalized epithelium and extend to replace the epithelia of the gastric pits.