Intrahepatic cholestasis by paucity of interlobular bile ducts in infancy.

On the basis of an extensive review of the literature and their personal experience, the authors consider that neonatal PILBD should not be regarded as merely a malformative anomaly of the bile excretory system, but as a delayed growth of the pars cystica of the hepatic bud in comparison with the normal growth pattern of the cranial part of the same hepatic bud. This leads to the development of hepatocytes and ductal plate, and these, in turn, are the origin of the perilobular or terminal bile ducts (Hering's ampullae) which eventually fuse with interlobular bile ducts for establishing the continuity of the bile duct system. The authors base this hypothesis on their L.M. and E.M. investigations and the casual observation of two cases in which the well documented bile duct anomaly eventually turned into a normal liver histology.