Hyaline cartilage at porta hepatis in extrahepatic biliary atresia.

Hyaline cartilage was found on microscopy of sections of the extrahepatic biliary tree in two infants with extrahepatic biliary atresia (EHBA). Respiratory epithelium was not present, and the cartilage did not seem to block the bile duct lumen. Hyperbilirubinemia was manifest in one infant on the second postnatal day, but clinical courses were otherwise unremarkable. In neither infant was the ductal plate malformation found on light microscopy of liver biopsy specimens, and in neither infant was visceral topography abnormal. Hyaline cartilage at the porta hepatis appears to be a novel finding in EHBA. Its significance remains to be defined.