A histopathological study of the liver in paraquat poisoning--an analysis of fourteen autopsy cases with emphasis on bile duct injury.

Fourteen autopsy cases of paraquat poisoning were studied. Seven of the eight patients who died within 4 days after the ingestion of paraquat showed hepatocytic injury, and three of them revealed bile duct injury. Hepatocytic injury was similar to that of carbon tetrachloride intoxication. Bile duct injury consisted of epithelial changes of the bile ductules and bile ducts. Cholestasis in the bile ducts was produced by the injury. The affected bile ductules and ducts had hydropic and necrotic epithelium, associated with the infiltration of neutrophils and histiocytes in the intraductal and periductal tissues. The severity of bile duct injury increased gradually from the bile ductules to the septal bile ducts. The extrahepatic biliary tract showed the same injury as the septal bile ducts in one case. It is considered that bile duct injury was produced by a direct corrosive effect of paraquat. Five of the six patients who survived more than 8 days revealed intrahepatic cholestasis, the pathogenesis of which was not clearly understood.