CYTOGENETIC AND MOLECULAR-GENETIC ANALYSIS OF A PEDIATRIC PLEOMORPHICSARCOMA REVEALS SIMILARITIES TO ADULT MALIGNANT FIBROUS HISTIOCYTOMA

Cytogenetic and molecular genetic studies were performed on a pleomorp hic sarcoma removed from the left atrium of a 15-year-old girl. Histol ogic analysis was consistent with a storiform-pleomorphic malignant fi brous histiocytoma (MFH). Although MFH is the most common soft-tissue sarcoma of late adulthood, it is extremely rare in childhood and its e xistence in the pediatric population remains controversial. Cytogeneti c analysis revealed several alterations previously associated with adu lt MFH, including abnormalities of chromosomal bands 11p11 and 19p13. Moreover, the tumor demonstrated homogeneously staining regions (HSR) and double minute chromosomes (dmin) suggestive of gene amplification. We therefore screened the case for amplification of genes localized t o chromosomal bands 12q13-14, including the putative protooncogenes MD M2, CDK4, SAS, CHOP, and GLI, which are frequently amplified and overe xpressed in adult MFH. Southern and Northern blot analysis confirmed t he coamplification of MDM2, CDK4, SAS, and CHOP. To our knowledge, suc h coamplification studies of the 12q13-14 amplicon have not been previ ously detected in pediatric MFH. Our results provide cytogenetic and m olecular genetic evidence that pediatric and adult MFH are histogeneti cally related entities. (C) Elsevier Science Inc., 1997.