Cytogenetic abnormalities in hepatoblastoma: report of two new cases and review of the literature suggesting imbalance of chromosomal regions on chromosomes 1, 4, and 12.

Two cases of hepatoblastoma with unique karyotypic changes are described. One case was that of a 2-year-old boy with an unbalanced chromosomal translocation involving 4q35 as the sole chromosomal abnormality. The clonal karyotype of this tumor was 46,XY,add(4)(q35)[3]/46,XY[9]. In the other case, that of a 2-year-old boy, karyotypic analyses revealed the clonal karyotype as 57,XY,+del(1)(p22),+2,+5,+6,+7,+8,+del(12)(p12),+18,+19,+20,+22[4]/46,XY[12]. Review of these two cases, together with previous reports, underscored the significance of numerical and/or structural chromosomal abnormalities of 1q, 4q, 2, 8, and 20 in the development of hepatoblastoma. The present results show that imbalance of the terminal region of 4q could be the sole chromosomal abnormality in a hepatoblastoma. We also found that imbalance of chromosomal regions on chromosomes 1 and 12 may contribute to the development of hepatoblastoma.