• Rare tumor
• Most common in 10- to 30-year-olds
• Poor prognosis
• Radiographic pattern usually lytic, destructive, and permeative
• Microscopic appearnce
  • Small cells juxtaposed to lobules of chondroid tissue
  • May have a hemangiopericytomatous appearance
  • May be difficult diagnose on biopsy if cartilage component has not been sampled
• Surgery is treatment mainstay
  • Some centers use chemotherapy based on osteosarcoma or Ewing sarcoma protocols as adjuvant therapy