CHROMOSOMES IN THE GENESIS AND PROGRESSION OF EPENDYMOMAS

Cytogenetic analysis was performed on cultures of primary ependymal tu mors with different degrees of malignancy (I-IV) obtained from four pa tients, none of whom had received therapy before karyotypic evaluation . The most common abnormalities were monosomy 17 and 22 in four cases and losses of sex chromosomes in three cases, Structural rearrangement s of chromosome 2 were a finding for all cases and involved loss of ma terial at 2q32-34. Other structural chromosome abnormalities detected involved chromosomes 4, 6, 10, 11, 12, and X. We also reviewed data on 22 cases previously reported.