Chromosome abnormalities of eighty-one pediatric germ cell tumors: Sex-, age-, site-, and histopathology-related differences - A Children's Cancer Group study

The chromosomes of 81 pediatric germ cell tumors (GCTs) were analyzed as pa rt of two clinical treatment trials, INT-0098 and INT-0097, conducted by th e Children's Cancer Group. The analysis of chromosome results showed differ ences with respect to sex, age, tumor location, and histology. Sixteen of 1 7 benign teratomas of infants and children less than 4 years old and from g onadal and extragonadal locations were chromosomally normal. Twenty-three m alignant GCTs from gonadal and extragonadal locations of the same age group were endodermal sinus tumors and varied in their karyotypic findings. The most common abnormalities were gains of Iq and chromosome 3. Of eight benig n ovarian teratomas from older girls, five with normal G-banded karyotypes were determined to be homozygous for Q-band heteromorphisms, suggesting a m eiosis II error. Among the 12 malignant ovarian GCTs from older girls, the common abnormalities were loss of Ip/gain of Iq, +3, +8, +14, and +21. Four of eight extragonadal tumors from older boys demonstrated +21; one had +X. Five of the eight had associated constitutional chromosome abnormalities, including one trisomy 21 and three with Klinefelter syndrome. The testicula r GCTs of adolescents had abnormalities resembling those found in adult tes ticular GCT, including near-triploidy, loss of chromosomes I I, 13, and 18, and gain of chromosomes 7, 8, the X chromosome, and an isochromosome 12p. The gain of an isochromosome 12p was only frequent in the tumors from adole scent boys. Deletion of Ip/gain of Iq and +3 were the most common abnormali ties among the malignant tumors from both sexes. (C) 1999 Wiley-Liss, Inc.