Human hepatocellular carcinoma and putative precancerous disorders: their enzyme histochemical study

An enzyme histochemical study was performed to investigate abnormal enzyme activity in human hepatocellular carcinoma (HCC) and, by application of these staining reactions to noncancerous liver disorders, to clarify the true nature of putative percancerous lesions. The enzyme activity of hepatocytes in cirrhotic livers, hepatitis B virus (HBV)-positive cells, and dysplastic liver cells was investigated. Although the tumor cells in HCC gave an intensively positive reaction for gamma-glutamyl transpeptidase activity at the cytoplasm and the whole-cell membrane, they were essentially deficient in glucose-6-phosphatase, alkaline phosphatase, acid phosphatase, and nonspecific esterase activities. Cirrhotic liver showed loss of the orderly zonal difference of enzyme activity that is present in normal liver. However, a pattern of enzyme deviation similar to that of HCC was not recognized anywhere. Neither HBV-positive hepatocytes nor dysplastic liver cells were shown enzymatically to be direct precusors of HCC.