Case 4:

Acute Rejection of Hepatic Allograft, Moderate Kay Washington, M.D., Ph.D. Pathology, C-3321 MCN Vanderbilt University Medical Center Nashville, TN 37232-2561

Clinical History This 27 year old man developed fulminant hepatic failure of unknown etiology and underwent liver transplantation. Two months later he presented with a slight fever (T=100 degrees F). Serum ALT was 1419 U/L, AST 772 U/L, total bilirubin 6.2 mg/dL, and alkaline phosphatase was 293 U/L. Cyclosporine level was low at 50 ng/mL. A liver biopsy was performed. Morphologic Findings The overall hepatic architecture is normal. The majority of portal tracts are expanded by an inflammatory infiltrate consisting of a mixture of small and large lymphocytes with scattered eosinophils and rare neutrophils. Lymphocytes infiltrate bile duct epithelium, making identification of interlobular bile ducts difficult. The biliary epithelial cells are swollen, resulting in obliteration of the bile duct lumen, and show reactive changes such as cytoplasmic vacuolization. Occasional bile ducts cells have pyknotic nuclei. In some portal tracts, lymphocytes infiltrate the subendothelial space of portal vein branches, lifting the endothelial cells. In the lobule, scattered acidophil bodies are seen, and there is canalicular cholestasis. Click on each slide thumbnail image for an enlarged view: Slide 11 Acute Rejection in Liver Allograft A mixed portal inflammatory infiltrate composed of mononuclear cells and scattered eosinophils and neutrophils is present. The interlobular bile ducts are infiltrated by lymphocytes; reactive changes in biliary epithelium such as nuclear enlargement and cytoplasmic vacuolization may also be seen. Slide 12 Acute Rejection in Liver Allograft In endothelialitis, inflammatory cells, predominantly lymphocytes, undermine the endothelium, resulting in detachment of endothelial cells from the underlying connective tissue. Endothelialitis is relatively specific for acute rejection, but is often not present in milder cases of rejection. Diagnosis: Acute Rejection, Moderate