Histopathological changes in the liver following a paracetamol overdose: correlation with clinical and biochemical parameters.

The histological appearances of the liver damage occurring after a paracetamol overdose are described in liver biopsies from 104 patients, of whom 38 developed fulminant hepatic failure. Confluent centrilobular necrosis of varying extent was followed by rapid disappearance of necrotic cells, leaving areas of reticulin collapse and a usually mild inflammatory reaction. The histological recovery in even the most severe cases was remarkable, and only one of the 17 survivors whose initial biopsy showed the pattern of interlobular bridging necrosis had appreciable residual fibrosis in a follow-up biopsy taken after 1 yr. A quantitative estimate was made of the amount of surviving liver parenchyma using a morphometric technique and the hepatocyte volume fraction (HVF) in biopsies performed within 10 days of the overdose correlated well with the clinical course and both the maximal prolongation of the prothrombin time and the peak plasma bilirubin concentration in the first 10 days. An HVF value (normal 85 +/- 5 per cent.) of less than 40 per cent. in a biopsy taken within 10 days of the overdose was found only in patients who died. However, HVF measurements on biopsies from three survivors taken later than 10 days after the overdose shows that survival is possible below this critical level.