Fluorescence in situ hybridization improves cytogenetic results in the analysis of hepatoblastoma.

ABSTRACT

Hepatoblastoma (HB) is the most frequent malignant liver tumor in children. Cytogenetic data indicate the presence of recurring trisomies of the chromosomes 2, 8, and 20, but more work is needed to clarify their incidence and prognostic significance. Cytogenetic analysis is limited by the requirement of suitable cells in metaphase. A different method that increases analysis sensitivity is fluorescence in situ hybridization (FISH). We studied 20 cases of hepatoblastoma; FISH analysis obtained results in 10 cases of HB with no informative karyotype. In 5 of 10 of these cases at least one trisomic clone was detected, which always coexisted with a population of diploid cells. These results confirm that trisomy 20 and/or 2 and 8 coexisting with diploid cells is a frequent finding in hepatoblastoma and provide further support to the clonal evolution theory indeed, trisomy 20 was the most frequently detected abnormality, followed by trisomy of chromosomes 2 and 8. In view of the high incidence of recurrent trisomies, FISH analysis should be recommended in all the cases of HB with no informative karyotype.