Significance of extra copies of chromosome 20 and the long arm of chromosome 2 in hepatoblastoma.

Cytogenetic analysis of both primary and metastatic hepatoblastoma revealed the following abnormal chromosomal complements respectively: 46,XX,der(2)t(2;2)(p25;q21),der(22)t(1;22)(q22;p13) [6]/47,XX,der(2)t(2;2)(p25;q21),+20,der(22)t(1;22)q22;p13)[4]/47,XX,der (2)t(2;2)(p25;q21), +20[1], and 48,XX,der(2)t(2;2)(p25;q21),+12,+17, -18,+20,der(22)t(1;22)(q22;p13)[9]/50,XX,der(2)t(2;2)(p25;q21), +8,+12,+17,+20[4]. Two abnormalities, the chromosome 2 derivative and trisomy 20, are recurrent in hepatoblastoma, but the derivative involving chromosomes 1 and 22 is a novel abnormality.