Chromosomal aberrations in a consecutive series of childhood rhabdomyosarcoma

Background and Procedure. During a 13-year period, 22 children were treated for rhabdomyosarcoma (RMS). In 18 of these patients chromosome analysis was attempted on material from tumor biopsies, fine needle aspiration biopsies and/or bone marrow samples. Results. Clonal chromosome aberrations were detected in 14 cases; 7 of 9 embryonal RMS, 6 of 8 alveolar RMS and in the single case of pleomorphic RMS. Cytogenetic failures were more frequent in fine needle aspiration biopsies than in tumor biopsies. The characteristic t(2;13) translocation was seen in 2 alveolar RMS but not in any of the other subtypes. In 3 of the embryonal RMS hyperdiploid or hypertetraploid karyotypes with few or no structural rearrangements were seen. In all 3 cases the clinical course was relativelv benign, suggesting that certain karyotypic patterns in RMS may be of prognostic significance. Conclusions. Our results add to the evidence that cytogenetic analysis should be an integral part of the diagnostic examinations of children with RMS.