Osteochondroma is a benign (noncancerous) tumor that bulges out at the end of the bone near the growth plate (area of growing tissue at the end of long bones).
Osteochondroma is the most common form of benign tumors in children. The bulge is caused by extra bone and cartilage that can grow on the surface of any bone, but it most commonly forms around the knee or upper arm. Osteochondromas can be located near nerves and can possibly cause nerve compression and numbness in the surrounding areas.
The exact cause of osteochondroma is unknown, but some experts believe there is a genetic abnormality that occurs during development in the mother’s womb.
Osteochondroma often has no symptoms and can go undiscovered for years or decades. If there are symptoms, they can include:
- Changes in growth patterns, especially slowing down
- Muscle weakness due to nerve compression
- Noticeable bump/bulge under the skin