Types of primary bone cancer are defined by which cells in the bone give rise to them.
Osteosarcoma
Osteosarcoma arises from bone-forming cells called osteoblasts in osteoid tissue (immature bone tissue). This tumor typically occurs in the arm near the shoulder and in the leg near the knee in children, adolescents, and young adults (3) but can occur in any bone, especially in older adults. It often grows quickly and spreads to other parts of the body, including the lungs. Risk of osteosarcoma is highest among children and adolescents ages 10 and 19. Males are more likely than females to develop osteosarcoma. Among children, osteosarcoma is more common in blacks and other racial/ethnic groups than in whites, but among adults it is more common in whites than in other racial/ethnic groups. People who have Paget disease (a benign bone condition characterized by abnormal development of new bone cells) or a history of radiation to their bones also have an increased risk of developing osteosarcoma.
Chondrosarcoma
Chondrosarcoma begins in cartilaginous tissue. Cartilage is a type of connective tissue that covers the ends of bones and lines the joints. Chondrosarcoma most often forms in the pelvis, upper leg, and shoulder and usually grows slowly, although sometimes it can grow quickly and spread to other parts of the body. Chondrosarcoma occurs mainly in older adults (over age 40). The risk increases with advancing age. A rare type of chondrosarcoma called extraskeletal chondrosarcoma does not form in bone cartilage. Instead, it forms in the soft tissues of the upper part of the arms and legs.
Ewing sarcoma
Ewing sarcoma usually arises in bone but may also rarely arise in soft tissue (muscle, fat, fibrous tissue, blood vessels, or other supporting tissue). Ewing sarcomas typically form in the pelvis, legs, or ribs, but can form in any bone (3). This tumor often grows quickly and spreads to other parts of the body, including the lungs. The risk of Ewing sarcoma is highest in children and adolescents younger than 19 years of age. Boys are more likely to develop Ewing sarcoma than girls. Ewing sarcoma is much more common in whites than in blacks or Asians.
Chordoma
Chordoma is a very rare tumor that forms in bones of the spine. These tumors usually occur in older adults and typically form at the base of the spine (sacrum) and at the base of the skull. About twice as many men as women are diagnosed with chordoma. When they do occur in younger people and children, they are usually found at the base of the skull and in the cervical spine (neck).
Several types of benign bone tumors can, in rare cases, become malignant and spread to other parts of the body (4). These include giant cell tumor of bone (also called osteoclastoma) and osteoblastoma. Giant cell tumor of bone mostly occurs at the ends of the long bones of the arms and legs, often close to the knee joint (5). These tumors, which typically occur in young and middle-aged adults, can be locally aggressive, causing destruction of bone. In rare cases they can spread (metastasize), often to the lungs. Osteoblastoma replaces normal hard bone tissue with a weaker form called osteoid. This tumor occurs mainly in the spine (6). It is slow-growing and occurs in young and middle-aged adults. Rare cases of this tumor becoming malignant have been reported.