Cytogenetic evaluation of a large series of hepatoblastomas: Numerical abnormalities with recurring aberrations involving 1q12–q21

Abstract

Hepatoblastoma is a malignant embryonal liver tumor that occurs almost exclusively in infants and very young children. Previous cytogenetic studies of hepatoblastoma have investigated small series or individual cases. This report is on the cytogenetics of a large series of 111 hepatoblastoma specimens, with cytogenetic results consecutively karyotyped over a 12-year period. Abnormal karyotypes were observed in 55 cases (approximately 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 1q12-21 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 1q12-21 also displayed numerical chromosome aberrations, the most common of which were chromosomal trisomies, whereas tumors with other structural rearrangements had fewer numerical abnormalities.

The genetic and epigenetic landscapes of hepatoblastomas

“…It is still not well established whether HB tumorigenesis is driven by changes in the copy number of genes mapped to these aneuploidies or whether such chromosomal changes already reflect mitotic errors inherent to HB development [46][47][48].…”

Liver Tumors in Children

“…Other compelling evidence suggests that acquired aberrations in the ␤-catenin/Wnt pathways are important in the pathogenesis of hepatoblastoma [29,30]. Acquired chromosomal changes in tumors include numerical chromosomal changes, most commonly trisomies of chromosomes 2, 8, and 20 [31]. Rearrangements involving the pericentric region of chromosome 1 also appear to be important in hepatoblastoma, with roughly 18% of hepatoblastomas displaying an imbalanced translocation involving this region [32,33].…”

Trisomy 8 as the sole chromosomal aberration in acute myeloid leukemia and myelodysplastic syndromes

“…For example, close to 50 cases of acute lymphoblastic leukemias (ALL), many of which of T-cell lineage, with +8 as the single anomaly have been published, and some solid tumor types/lesions, in particular desmoid tumors and Dupuytren's contracture, are also characterized by this abnormality [16][17][18]. Trisomy 8 is also common together with other chromosomal aberrations in a large number of tumor types, such as colon, breast, and head and neck cancer [19][20][21], Wilms tumor [22], and hepatoblastoma [23].…”