Wednesday, December 29, 2010

Early Chronic Rejection in a Liver allograft.

45 y/o status post liver transplant 1 year ago with increasing ALP over time

Early chronic rejection usually shows degenerative changes of the majority of the smaller bile ducts, ductopenia involving less than 50% of the portal tracts, and centrilobular hepatocyte dropout/fibrosis. The degenerative changes consists of eosinophilic transformation of the cytoplasm, nuclear hyperchromasia, uneven nuclear spacing, and sloughing of bile duct epithelial cells, as seen in this case.

The distinction between bile duct obstruction/stricturing and chronic rejection may be difficult. The presence of a marked ductular reaction and prominent periportal copper deposition favors bile duct obstruction/stricturing (primary or secondary) while the absence of a ductular reaction, absence of periportal copper deposition, and the presence of pericentral vein hepatocyte dropout/fibrosis favors chronic rejection.

Immunohistochemical staining for CK19 to highlight the bile ducts and ductular reaction as well as histochemical staining for peri-portal copper may be useful in the workup of liver allograft cases with biliary abnormalities.