• High-grade spindle cell tumor
  • Very poor prognosis; most patients die within 2 years of diagnosis
  • Age and skeletal sites very similar to regular chondrosarcoma
  • Microscopic appearance
    • High-grade sarcomatous elements of fibrosarcoma or malignant fibrous histiocytoma juxtaposed to conventional chondrosarcoma
  • Surgery is treatment mainstay
    • Osteosarcoma-type chemotherapy used in some centers
    • Outcome with chemotherapy likely worse than in osteosarcoma