list four characteristic features of osteosarcoma.

Ccharacteristic features is bellow.

1. Bone pain or tenderness.
2. A mass or lump (tumour) that is warm and might be felt through your skin
3. Swelling and redness at the site of your tumour.
4. Increased pain with lifting (if it affects your arm).
5. Limping (if it affects your leg)