Cytogenetic evaluation of a large series of hepatoblastomas: Numerical abnormalities with recurring aberrations involving IqI2-q2I

Hepatoblastoma is a malignant embryonal liver tumor that occurs almost exclusively in infants and very young children. Previous cytogenetic studies of hepatoblastorna have investigated small series or individual cases. This report is on the cytogenetics of a large series of I I I hepatoblastorna specimens, with cytogenetic results consecutively karyotyped over a 12-year period. Abnormal karyotypes were observed in 55 cases (similar to 50% of the total). Numerical aberrations were observed in 41 cases (36% of the total), particularly trisomies of chromosomes 2, 8, and 20. Chromosome losses were less common than chromosome gains. Structural abnormalities were observed in 43 cases (39% of the total). Unbalanced translocations resulting in trisomy 1q and involving breakpoints at 1q 12-21 were the most common structural abnormality, observed in 20 tumors (18% of total cases); the corresponding translocated chromosome was highly varied. The previously reported t(1;4) was observed in seven cases. Most tumors with translocations involving 1q 12-21 also displayed numerical chromosome aberrations, the most common of which were chromosomal trisomies, whereas tumors with other structural rearrangements had fewer numerical abnormalities. Supplementary material for this article can be found on the Genes, Chromosomes, and Cancer website at http:// www.interscience.wiley.com/jpages/1045-2257/suppmat/index.html. (c) 2005 Wiley-Liss, Inc.