Significance of intestinal metaplasia for the evolution of cancer in the biliary tract.

Of 25 cases of cancer in the intrahepatic bile ducts, 44 cases of cancer in the extrahepatic bile ducts, 30 cases of adenoma in the gallbladder, and 100 cases of infiltrating carcinoma in the gallbladder, several to about 20% of the cases showed Paneth's cell metaplasia and/or enterochromaffin cell metaplasia within the tumor mass or in its surrounding mucosa. These metaplasia were not found in small adenomata of the gallbladder, but they were frequently seen in large adenomata. Goblet cell metaplasia and marked hyperplasia of mucous glands were seen more frequently in the mucosa surrounding cancer than in the mucosa of 500 non-neoplastic gallbladders. Although cancer in the gallbladder occasionally developed on the basis of intestinal metaplasia alone, intestinal metaplasia was not likely to be related to induction of most adenomata, but it was likely to be associated with growth and cancerous change of adenoma.