Types of mucosal metaplasia in relation to the histogenesis of gastric carcinoma.

One hundred thirty-nine surgically resected stomachs and 16 stomachs obtained at necropsy in China were studied histochemically to evaluate the types and distribution of mucosal metaplasia in relation to benign and malignant disease. Three classes of mucin were distinguished: small-intestinal (N-acylated sialomucin); colonic (sulfated and O-acylated sialomucin); and gastric (neutral mucin). Small-intestinal type of metaplasia (SIM) occurred in 95% of instances of atrophic gastritis, 36% of cases of superficial gastritis, 60% of cases of gastric ulcers, and 39% of cases of duodenal ulcers. Colonic type of metaplasia (CIM) was less common and was found in only 11% of benign lesions. It was located in the antrum, particularly on the lesser curvature. Mucin was present in 66 of 84 carcinomas. The stomach tumors fell into three histochemical groups: colonic (acid mucin), 32; gastric (neutral mucin), 19; and mixed (acidic and neutral), 15. In 94% (30/32) of colonic type of gastric carcinoma, CIM was present. Thus, CIM is related to development of colonic type of gastric carcinoma, whereas SIM is a nonspecific reaction to mucosal damage.