Most common malignant bone tumour. Osteoid produced by a proliferating spindle cell stroma. Usually aged 10-25 or >40 years; M=F.
Most common around knee
Initial symptom is painful bony mass with swelling – sensitive to palpation; may have fever
Elevated alkaline phosphatase.
X-ray – variable – usually have Codman’s triangle or sunburst periosteal reaction
Poor survival from surgery alone – with chemotherapy, 5 year survival rate is 50%.