What causes osteosarcoma?

Osteosarcoma arises from cells involved in making new bone, often in a long bone near a joint. The genetic changes that start it are usually acquired during a person's life rather than passed directly from a parent. A small group of inherited cancer-predisposition conditions, including Li-Fraumeni syndrome, can increase susceptibility. Previous treatment involving radiation to a bone may also be relevant. An injury does not create osteosarcoma, although pain after an injury may bring attention to a tumour that was already developing.

Arrange an assessment for persistent or worsening bone pain, swelling, a firm lump, reduced movement, or a fracture after minor force. The evaluation may include an examination, an X-ray, other imaging, and blood tests. If imaging shows a concerning area, a specialist plans a biopsy carefully because the biopsy route can affect later surgery. Bring details about symptom timing, previous radiation, and relevant family cancer history.

Seek urgent care for sudden severe limb pain, a new deformity, inability to bear weight, loss of sensation, or a cold or pale limb. These signs can indicate a fracture or pressure on nerves or blood vessels. Rapidly increasing swelling or pain that disrupts sleep also merits prompt clinical review.

What other causes could explain this bone pain or swelling? Which scan is appropriate? If a biopsy is needed, who should plan it? Does my family history suggest a genetic consultation?