Comparative genomic hybridization of microdissected samples from differentstages in the development of a seminoma and a non-seminoma

Human testicular germ cell tumours (TGCTs) of adolescents and adults, both seminomas and non-seminomas, originate from intratubular germ cell neoplasi a (IGCN). Comparative genomic hybridization (CGH) was applied to microdisse cted samples from different stages of the development of a seminoma and a m ixed non-seminoma, including IGCN of both. The different stages of the semi noma development, namely IGCN, intratubular and invasive seminoma, showed a very similar pattern of chromosomal imbalances, including gains of parts o f 7, 8,12,14, and X, and losses of parts of 3, 4, 5, 10, 11, 12q, 16, 18, 2 2, and Y. A more heterogeneous pattern was found for the non-seminoma. Some aberrations were present only in IGCN, or in IGCN and in all invasive comp onents (gains of parts of 1q, 17, 19p, 20q, and 22, and losses of parts of 4, 5, 9p, 13, and 18q), while others were present in a less consistent patt ern. These are the first reported CGH data from different stages in the dev elopment of TGCTs. Although only two cases were studied, the results sugges t that particular numerical changes of (parts of) chromosomes are involved in the early development and progression of this cancer. Copyright (C) 2000 John Wiley & Sons, Ltd.