Karyotype studies in 18 ependymomas with literature review of 107 cases.

Cytogenetic studies from 17 pediatric ependymomas and 1 ependymoblastoma are presented. Eight tumors had abnormal karyotypes. Another 107 published cases of cytogenetic analyses from pediatric and adult ependymomas or ependymoblastomas were reviewed. Of the total 125 tumors, 83 (66%) had abnormal karyotypes, of which 24 had a sole autosomal abnormality. Approximately one third had monosomy 22 (-22) or breakpoint 22q11-13, with a higher incidence in adult (56%) versus pediatric (28%) tumors. Structural abnormalities of chromosomes 1, 6, and 17, and numerical abnormalities of 7, 9, 12, and 20, in particular, are also discussed. Although no primary cytogenetic abnormality is evident, these findings may provide direction for additional investigations regarding the classification of these tumors.