Bone tumours

Bone tumours are cancers that start in a bone. It is sometimes called a bone sarcoma. 

There are two main types of bone tumours in children.


Osteosarcoma starts in cells called osteoblasts, which are cells that form new bone. Osteosarcoma usually develops at the ends of the long bones, such as the arms or legs.

This type of tumour often starts in bones that are growing quickly, making it more common in teenagers during their growth spurt than in young children. Osteosarcoma is very rare in children under five years old.1

Ewing sarcoma

Ewing sarcoma (also called Ewing family of tumours) forms from a type of stem cell in the bone marrow. Ewing tumours can form in the bones of the:

  • arms
  • legs
  • hands
  • feet
  • spine
  • skull
  • ribs
  • shoulder blades 
  • hips.

Ewing sarcomas can also form in soft tissues near bones. These are called extraosseous or extraskeletal Ewing tumours. The Soft tissue sarcoma section has some information about these types of tumours.

Ewing tumours are also more common in teenagers than in young children.