Syndromatic paucity of interlobular bile ducts: hepatic histopathology of the early and endstage liver.

Morphologic findings of the liver in syndromatic paucity of intrahepatic bile ducts (SPIHBD) during infancy include paucity of interlobular bile ducts, features of "giant cell hepatitis," dilated lymphatics and veins in the portal tract, perisinusoidal fibrosis, and bile duct epithelial changes with a concentric layering of mesenchymal cells around bile ducts reminiscent of renal dysplasia. The latter change is characteristic of SPIHBD. Although the disease is characterized by paucity of bile ducts, morphometric studies show paucity of interlobular bile ducts in less than half of the patients during infancy. Reduced numbers of portal tracts and increased percentage of portal tracts devoid of bile ducts are more constant findings. It was impossible to predict from the early biopsy which patients would develop more severe portal fibrosis. Later in the disease portal fibrosis is variable and unevenly distributed, being more severe near the hilum regardless of the prior performance of a Kasai-type operation or the state of patency of the extrahepatic bile ducts. Hypoplasia of the extrahepatic bile ducts is the usual finding in SPIHBD, but if atresia of extrahepatic bile ducts is associated with intrahepatic paucity of bile ducts, the hepatic histopathology is that of PIHBD. Recognition of PIHBD would avoid unwarranted surgical procedures.