Histopathology of the liver in pediatric patients following transplantation

Recognition of rejection and other hepatic complications by needle biopsy plays a significant role in the management of liver allograft recipients. In this report, 22 pediatric patients (below 18 years old) were selected from the 37 liver transplants. Seven of the 22 cases have an uneventful posttransplant course. The most common cause of allograft injury in these patients appeared to be acute cellular rejection. It occurred in 7 (31.8 %) of the 22 cases and was the primary process in 8 of the 25 episodes of liver dysfunction. Other etiologies, such as opportunistic viral infection (3 cases), biliary obstruction (2 cases), preservation injury (1 case), and vascular obstruction (1 case) were less common. Acute graft rejection causing liver dysfunction was associated with a mixed portal inflammation, destruction of the interlobular bile ducts, and varied degree of venous endotheliitis, followed by centrilobular hepatocyte necrosis. Chronic rejection was not seen in our pediatric cases. Cold ischemic injury causing transient graft dysfunction as seen in one of our patients demonstrated focal, limited areas of hepatocyte necrosis, mild centrilobular hepatocyte ballooning, and cholestasis without evidence of bile duct damage. More severe ischemic injury resulted from vascular complication causing diffuse hepatocyte necrosis was seen in one patient with hepatic vein thrombosis. The histologic patterns observed were not pathognomic; however, liver biopsies were helpful in suggesting the probable cause of liver dysfunction and in predicting subsequent allograft recovery when used in conjunction with clinical information, radiologic, and other laboratory tests.