Dedifferentiated chondrosarcoma: radiographic features.

Dedifferentiated chondrosarcomas, unlike ordinary chondrosarcomas, are highly aggressive tumors that frequently metastasize. The lesion is characterized by a lytic intraosseous or extraosseous soft-tissue mass that is devoid of the calcifications that are usually associated with a chondroid tumor. We describe the radiographic and pathologic features of five cases involving dedifferentiated chondrosarcoma.