Endocrine cells in extrahepatic bile duct carcinoma

A total of 44 extrahepatic bile duct carcinomas comprising 13 well-differentiated adenocarcinomas, 25 moderately differentiated adenocarcinomas, and 6 poorly differentiated adenocarcinomas were examined histologically and immunohistochemically for somatostatin, gastrin, and glicentin. Argyrophil cells, argentaffin cells, and somatostatin- and gastrin-immunoreactive cells within the tumor were detected in 46.2%, 15.4%, 23.1%, and 15.4% of well-differentiated adenocarcinomas, and in 16.0%, 8.0%, 12.0%, and 4.0% of moderately differentiated adenocarcinomas, respectively. No tumor tissues of poorly differentiated adenocarcinomas contained endocrine cells. A statistically significant difference in the frequency of argyrophil cells was observed between well and poorly differentiated adenocarcinoma. The incidence of argyrophil cells and somatostatin-immunoreactive cells in nonneoplastic mucosa adjacent to well-differentiated adenocarcinoma was higher than in that adjacent to poorly differentiated adenocarcinoma. Glicentin-immunoreactive cells could not be demonstrated either in tumor tissue or in nonneoplastic mucosa of the extrahepatic bile duct. With reference to the histogenesis of extrahepatic bile duct carcinoma, it was assumed from these results that the development of well-differentiated adenocarcinoma might be closely related to the occurrence of endocrine cells and that poorly differentiated adenocarcinoma might develop from ordinary mucosa.