CYTOGENETIC ANALYSIS OF 109 PEDIATRIC CENTRAL-NERVOUS-SYSTEM TUMORS

Reports of cytogenetic abnormalities in pediatric central nervous syst em (CNS) tumors are important for collection and comparison of large n umbers of karyotypes of primary CNS neoplasms to produce statistically significant correlations. We report cytogenetic results of 119 sample s of pediatric CNS tumors from 109 patients. Tumors included 33 low-gr ade astrocytomas, 18 high-grade astrocytomas, 14 gangliogliomas, 13 ep endymomas, 17 primitive neuroectodermal tumors (PNET), three choroid p lexus papillomas and carcinomas, and a miscellaneous group of to rare primary CNS tumors and metastases. In each group, cytogenetic results were correlated with histologic subtype and survival. The study indica ted specific chromosome abnormalities in different groups of tumors. L ow-grade astrocytomas showed mostly numeric abnormalities with gains o f chromosome 7, high-grade astrocytomas showed differences from karyot ypic changes observed in adults in lacking double minutes (dmin) and m onosomy 10. The ependymoma group showed the largest proportion of abno rmal karyotypes with frequent involvement of chromosome 6 and 16. Chro mosome 6 was the single most common abnormal chromosome in this study, closely followed by chromosomes 1 and 11. Pediatric CNS neoplasms dif fer from adult tumors cytogenetically as well as histologically and bi ologically.