The ultrastructural characteristics of liver progenitor cell types of human atypical ductular
reactions seen in chronic cholestasis, in regenerating human liver after submassive
necrosis, in alcoholic liver disease, and in focal nodular hyperplasia are compared with liver
progenitor cell types seen during experimental cholangiocarcinogenesis in hamsters; during
hepatocarcinogenesis in rats; and in response to periportal liver injury induced by allyl
alcohol in rats. Three types of progenitor cells have been identified in human atypical …