Bone tumors may be benign (noncancerous) or malignant (cancerous). Benign bone tumors are more common than malignant ones. Both types may grow and compress healthy bone tissue and absorb or replace it with abnormal tissue. However, benign tumors do not spread and are rarely life-threatening

The most common type of bone cancer is osteosarcoma, which develops in new tissue in growing bones. Another type of cancer, chondrosarcoma, arises in cartilage. Evidence suggests that Ewing’s sarcoma, another form of bone cancer, begins in immature nerve tissue in bone marrow. Osteosarcoma and Ewing’s sarcoma tend to occur more frequently in children and adolescents, while chondrosarcoma occurs more often in adults.