[Cystic diseases of the liver. From embryology to malformations]

Cystic diseases of the liver which are in most cases hereditary, are related to an embryonic disorder know as ductal plate malformation. These diseases correspond to partial or total arrest of remodeling of the ductal plate, leading to more or less complete persistence of the excess of embryonic biliary structures. The ductal plate malformation may concern different segments of the intrahepatic biliary tree (segmental bile ducts, interlobular bile ducts and the smallest bile duct ramifications) leading to various pathoclinical entities. Caroli's disease is characterized by persistent dilated large intrahepatic bile ducts and appears to be the result of a factor acting during the early period of bile duct embryogenesis. Congenital hepatic fibrosis is characterized by ductal plate malformations of more distal, interlobular, bile ducts, and could be due to a factor that acts later on during bile duct development. This disorder may be isolated or associated with malformations of large, segmental, intrahepatic bile ducts. Von Meyenburg complexes and autosomal dominant polycystic liver disease are related to ductal plate malformation of more peripheral interlobular bile ducts and caused by a factor intervening in the later phase of bile duct embryogenesis. The genetic or non genetic factors leading to these ductal plate malformations are unknown.