Trisomy 1 and 8 occur frequently in hepatocellular carcinoma but not in liver cell adenoma and focal nodular hyperplasia. A fluorescence in situ hybridization study.

Conventional cytogenetic studies revealed gains and structural aberrations of chromosome 1 to be the most consistent chromosomal aberrations in hepatocellular carcinoma (HCC). We investigated touch preparations of eight HCC, five cholangiocellular carcinomas (CCC), five liver cell adenomas (LCA), four focal nodular hyperplasias (FNH) as well as nine specimens of normal liver tissue using fluorescence in situ hybridization (FISH) with centromere specific probes for chromosomes 1 and 8. Polysomies of chromosome 1, especially trisomy 1, were found in five of eight HCC and four of five CCC but in no normal liver tissue or benign tumour. Only three of seven cases of HCC revealed trisomy 8 whereas the five benign liver tumours and all normal liver tissues examined had disomy 8. Our results confirm conventional cytogenetic findings in terms of chromosome 1 aberrations in HCC although they are not specific for these types of malignant liver tumours. Since alpha-satellite probes were used in our study, only gains or losses including the centromeric regions of the chromosomes 1 and 8 could be detected. Nevertheless, our findings suggest that FISH may help in the differential diagnosis of malignant versus benign neoplasms of the liver.