3 TYPES OF LIVER-CELL DYSPLASIA (LCD) IN SMALL CIRRHOTIC NODULES ARE DISTINGUISHABLE BY KARYOMETRY AND PCNA LABELING, AND THEIR FEATURES RESEMBLE DISTINCT GRADES OF HEPATOCELLULAR-CARCINOMA

We have studied the occurrence and specific features of liver cell dys plasia (LCD) in Chinese patients showing liver cirrhosis with or witho ut hepatocellular carcinoma (HCC). Three types of LCD (SLCD, LLCDo, LL CDe) were morphologically defined, and these types were further analyz ed using karyometry, estimation of nucleic acid content and density, a nd PCNA immunostaining. Features found for three types of LCD were com pared with those of normal hepatocytes (NLC), simple regenerating hepa tocytes (SRLC), and cells of HCCs covering different grades. The resul ts show that 1) karyometry and nucleic acid parameters allow an object ive separation of LCD types both from NLC and SRLC; 2) karyometric fea tures of LLCDe are most close to those of highly differentiated HCCs, whereas nuclear size and chromatin composition of SLCD closely reflect those of poorly differentiated HCCs; 3) the frequency of LCD clusters was higher in cirrhotic livers carrying HCC, being about double for a ll three LCD types; 4) the highest PCNA labelling occurred in the smal l cell group of LCD (SLCD), still, however, being smaller than that of simple regenerating hepatocytes. Based on these findings it is sugges ted that, similar to atypical adenomatous hyperplasia, LCDs of distinc t morphotypes may represent precursor lesions for HCC, and some cellul ar forms may mimick cell types known to occur in experimental carcinog enesis.