Immunohistochemistry of carcinoembryonic antigen, secretory component and lysozyme in benign and malignant common bile duct tissues.

An immunoperoxidase technique has been utilized for the localization of carcinoembryonic antigen (CEA), secretory component (SC) and lysozyme ( LZ ) in normal and cancerous common bile duct tissues. Little or no CEA was found in the non-cancerous common bile duct tissues. SC was found in the surface epithelium and accessory gland epithelium and LZ was demonstrated only in the accessory glands. Some inflammatory cells were also positively stained for LZ . In adenocarcinoma, CEA was always present on the luminar border of the carcinoma cells, occasionally with intercellular and intracellular localization. LZ was absent, or only faintly detected in carcinoma. SC was generally distributed in well-differentiated adenocarcinoma cells, but showed a reduced intensity of staining with progressive dedifferentiation. These findings suggest that CEA, SC and LZ could be useful markers providing valuable information in the pathological diagnosis of bile duct carcinoma.