Cytogenetic findings in a case of dedifferentiated chondrosarcoma.

Cytogenetic analysis of a case of dedifferentiated chondrosarcoma with a malignant fibrous histiocytoma (MFH) component revealed a near-triploid karyotype with multiple copies of chromosome 7, deletion of chromosome arm 9p, and a derivative chromosome 19 [add(19p)] in each metaphase. Whereas numerical anomalies of chromosome 7 have been frequently reported in chondrosarcoma, deletion 9p and add (19p) have been observed in MFH. A putative MFH tumor suppressor gene could be present in a critical region on chromosome bands 9p21~p22.