Fibrous tumors in children - A morphologic and interphase cytogenetic analysis of problematic cases

We describe and discuss the findings by fluorescent in situ hybridization ( FISH) for detection of non-random chromosomal gains, in a group of unusual fibrous lesions in children. Nuclear disaggregation was used to prepare sli des from eight cases which were hybridized using alpha-satellite enumeratio n probes for chromosomes 8, 11 and 17. Trisomy 8 and 11 were detected in a high percentage of nuclei in cases of congenital/infantile fibrosarcomas (r anging from 45 to 80%), and in a low grade fibrosarcoma in an older child ( 23%). Only gains of chromosome 17 were detected in a case of infantile fibr omatosis (22%). In this study we have found that given the unconventional h istopathologic features, the detection of more than one non-random chromoso mal gains by FISH, may aid in further defining fibrous tumors in children, and may be useful as an ancillary diagnostic test in the future.