Orthopedic cancers begin as benign (noncancerous) or malignant (cancerous) tumors, abnormal growths of cells, within the bone and muscle. Benign orthopedic tumors are more common and are rarely life-threatening.

Osteochondroma is the most common benign bone tumor. It is more common in people under age 20. Giant cell tumor is a benign tumor, typically in the leg (malignant types of this tumor are uncommon). Osteoid osteoma is a bone tumor, often found in long bones, that happens commonly in the early twenties.

Orthopedic oncologists are medical doctors and surgeons who specialize in the diagnosis and treatment of primary bone cancers, or cancers that begin in a person's bones. Primary bone cancer is a rare disease, however, accounting for less than 0.2% of all cancers.