INTERPHASE CYTOGENETIC ANALYSIS REVEALS NUMERICAL CHROMOSOME-ABERRATIONS IN LARGE LIVER-CELL DYSPLASIA

Background/Aims: Little is known about genetic alterations in large or small liver cell dysplasia. The aim of this study was to determine wh ether these lesions present numerical chromosome aberrations. Methods: Eight patients with hepatocellular carcinoma on cirrhosis, five with large liver cell dysplasia and three with small liver cell dysplasia, were analysed by in situ hybridization with different centromeric nucl eic acid probes specific respectively for chromosomes 1, 7, 17 and 18, In each case results were compared between dysplastic, tumoral and no n-dysplastic cirrhotic cells, Four normal livers were also studied wit h the same method and served as cytogenetic controls. Results: All cas es of large liver cell dysplasia dysplayed a polysomic population for each investigated chromosome, A high variability of numerical chromoso me aberrations was observed with a copy number of chromosomes which ra nged from two to more than six, By contrast, only one case of small li ver cell dysplasia showed chromosomal anomalies. Numerical aberrations of at least one chromosome were observed in six of the eight hepatoce llular carcinoma while the non-dysplastic cirrhosis and normal liver a lways showed a diploid pattern. Conclusions: These results demonstrate that cellular modifications in large liver cell dysplasia coexist wit h an early acquisition of genomic alterations, supporting the view tha t these phenotypic changes are preneoplastic.