INTESTINALIZATION OF GASTRIC SIGNET-RING CELL CARCINOMAS WITH PROGRESSION

Recent developments in mucin histochemistry and immunohistochemistry h ave made reliable determination of the gastric and intestinal phenotyp es of gastric carcinoma cells possible. Phenotypic expression changes from gastric epithelial cell type to intestinal epithelial cell type w ith the growth of gastric tumours in experimental animals. We studied cell differentiation in gastric signer ring cell carcinomas with progr ession in 203 surgically obtained specimens. The results showed that t he proportion of gastric phenotype carcinomas, in which over 90% of th e tissue consists of gastric epithelial cell type cells, decreases wit h the depth of invasion. The proportion of mixed phenotype carcinomas (between 10% and 90% of the tissue made up of gastric and/or intestina l epithelial cell type cells) increases. The intestinal phenotype (ove r 90% intestinal epithelial cell type carcinoma cells) was found in fo ur carcinomas (about 2%) involving the serosa. No clear relationship w as evident between phenotypic expression of carcinoma cells and the de gree of intestinal metaplasia of the surrounding mucosa. Progression o f gastric signet ring cell carcinomas is associated with a phenotypic shift from gastric to intestinal type expression.