Ductular and Cholangiocellular Lesions of the Liver

Primary liver cancer may derive from hepatocytes or bile duct cells. Recently it has been suggested the progenitor cell compartment is also a target cell population for carcinogenesis (1). Hepatic progenitor cells (HPC) are located in the most peripheral branches of the biliary tree, i.e., the ductules and canals of Hering. Biliary epithelium is normally CK7 and CK19 positive. HPC are also immunoreactive to CK7, CK19, oval cell markers OV6 and OV1, neural cell adhesion molecules (NCAM), chromogranin-A, etc. Bile ductules, irrespective of being derived from HPC or from metaplasia of the hepatocytes, express cytokeratins of biliary pattern including CK7, CK8, CK18, and CK19, whereas mature hepatocytes express CK8, CK18, Hepar-1 and albumin (2,3).