Cytogenetics in ovarian cancer has been restricted to conventional cytogenetic analysis of G-banded metaphase chromosomes up to the early 1980s. The detection of cytogenetic changes in solid tumors was relatively limited, as cytogenetic preparations from solid tumor tissue often have a low yield of metaphases with poor quality chromosomes (1 ). Following the advent of the fluorescence in situ hybridization (FISH) technique (2 ,3 ) it became possible to obtain huge amounts of additional cytogenetic information from the material available. This fact is demonstrated very clearly by the following comparison: Mitelman summarizes in the 4th edition of Catalog of Chromosome Aberrations in Cancer only 185 cases of ovarian cancer, which were characterized by conventional cytogenetic analysis between about 1970 to 1991 (4 ). On the other hand, 135 cases of ovarian cancer have been analyzed by means of comparative genomic hybridization (CGH) in the shorter time period 1995 to 1997 (5 -8 ).