X-RayMusculoskeletalAdvanced

Osteosarcoma (Codman triangle)

musculoskeletalbone tumouroncologycodman trianglesunburstknee

Clinical presentation

Adolescent with progressive pain and swelling around the knee, worse at night, without a clear history of trauma.

Key imaging findings

  • Aggressive mixed lytic–sclerotic metaphyseal lesion around the knee
  • Aggressive periosteal reaction: Codman triangle and sunburst/spiculated pattern
  • Wide zone of transition with cortical destruction
  • Cloud-like new bone (osteoid matrix) and an associated soft-tissue mass

Form your diagnosis, then reveal the answer.

Educational teaching content only. Imaging appearances vary; always correlate clinically and confirm with a qualified radiologist.