Mucin-histochemical and immunohistochemical profiles of epithelial cells of several types of hepatic cysts.

Epithelial cells of several types of hepatic cysts were examined by mucin histochemistry and immunohistochemically. There were some differences in mucus and antigenic expression among the hepatic cysts examined. Epithelial cells of non-parasitic simple cysts and adult-type polycystic liver showed similar mucin-histochemical and immunohistochemical features, and were characterized by little mucin and weak immunoreactivities to several antibodies examined. Epithelial cells of hepatic hilar cysts were characterized by much mucin and moderate immunoreactivities to carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA). Epithelial cells of ciliated hepatic foregut cysts were characterized by much mucin and immunoreactivities to actin and tubulin which were positive in cilia. Epithelial cells of biliary cystadenoma were characterized by much mucin and moderate to strong immunoreactivities to cytokeratins CAM5.2 and AE1 and 3 as well as to CA 19-9, CEA, EMA and DU-PAN-2. Epithelial cells of biliary cyst-adenocarcinoma were characterized by much mucin and moderate to strong immunoreactivities to cytokeratins CAM5.2 and AE1 and 3 as well as to CA 19-9, CEA, EMA and DU-PAN-2. These differences in epithelial mucus and antigenic expression among several types of hepatic cysts may reflect differences in their origin and biological characteristics. These differences may be helpful in the differential diagnosis of hepatic cysts in small biopsy specimens.