Intestinal mucinous substances in gastric intestinal metaplasia and carcinoma studied by immunofluorescence.

Immunofluorescent studies using specific antisera against intestinal mucins revealed small intestinal mucin antigen (SIMA) and large intestinal mucin antigen (LIMA) in areas of intestinal metaplasia of the stomach. In 25 gastric carcinomas studied, both these antigens were detected in seven carcinomas, SIMA only was present in four and LIMA in only four cases; the antigens could not be detected in ten of the carcinomas. In 21 of the 25 gastric operation specimens, including the 15 carcinomas positive for intestinal mucin antigens, there was evidence of chronic gastritis and intestinal metaplasia. These immunohistologic observations confirm the results of recent histochemical studies that both small and large intestinal type mucins are present in intestinal metaplasia and gastric carcinomas. Our findings provide further evidence that at least a proportion of gastric carcinomas may supervene on intestinal metaplasia. The absence of one or both antigens in gastric carcinomas may indicate stages of dedifferentiation or alternatively differences in histogenesis.