Extraskeletal tumours of bone and cartilage
Cancerous tumours made up of bone and cartilage tissue can develop outside of the bone. These tumours are described as extraskeletal. Extraskeletal tumours of bone and cartilage may also be called extraskeletal chondro-osseous tumours.
Extraskeletal osteosarcoma is also called extraosseous osteogenic sarcoma. It is a very rare tumour that develops in the soft tissues around the bone, but not in or on the bone itself.
Most extraskeletal osteosarcomas occur in the arm or leg. They can also develop in the breast, retroperitoneum (back of the abdominal cavity), bladder or other internal organs. Most of these tumours are high grade, which means they grow quickly and can spread, or metastasize, to other parts of the body.
Extraskeletal chondrosarcoma is a rare type of soft tissue sarcoma. It often starts in the soft tissues of the upper arms or hands. It can also start around limb girdles, which are the areas where the long bones attach to the trunk of the body.
These tumours occur most often in people older than 35 years of age. They are almost twice as common in males as in females.