Dedifferentiated Chondrosarcoma:A Report of a Case With Immunohistochemical, Ultrastructural, and Cytogenetic Analysis and Review of the Literature

We describe the clinicopathologic and cytogenetic findings of an unusual dedifferentiated chondrosarcoma with a rhabdomyosarcomatous component in a case report and review the relevance of these findings with respect to seven previously reported cases. Cytogenetic studies of dedifferentiated chondrosarcoma are limited to 2 previously described cases, both with dedifferentiated components distinct from this case. In this study, cytogenetic analysis of 3 separate specimens, biopsy with chondrosarcoma, definitive surgical, and lung metastasis with rhabdomyosarcomatous component, revealed clonal karyotypic aberrations in each. A structural abnormality involving the short arm of chromosome 17 and extra copies of chromosomes 5, 7, 12, and 20 were common to all three specimens. These findings reveal multiple shared chromosomal anomalies between the primary chondrosarcoma and the dedifferentiated components, which suggests a clonal evolution. Int J Surg Pathol 2(4):319-328, 1995.