DIFFERENTIATION TOWARDS GASTRIC FOVEOLAR, MUCOPEPTIC AND INTESTINAL GOBLET CELLS IN GALLBLADDER ADENOCARCINOMAS

Cellular differentiation in 22 surgically removed adenocarcinomas of t he gallbladder was immunohistochemically studied with antibodies speci fic to mucins of gastric foveolar cells (M1), (pseudo)pyloric cells (M 2) and intestinal goblet cells (MS), and also with antibodies against pepsinogen II and chromogranin A. More than 70% of tumours (16 of 22 c ases) displayed gastric- and/or intestinal-type differentiation, most of which (12 of 16 cases) showed both types of differentiation. Two tu mours showed an organoid growth pattern similar to the normal gastric mucosa, The presence of endocrine cells positive for chromogranin A wa s closely related to that of gastric- and/or intestinal-type cells. Th e present findings clearly indicate the multidirectional differentiati on of gallbladder adenocarcinomas and suggest that most gallbladder ad enocarcinomas develop and progress under induction of gastric and inte stinal differentiation.