Also called osteocartilaginous exostoses, osteochondroma is an overgrowth of cartilage and bone near the end of the bone near the growth plate. This type of overgrowth can occur in any bone where cartilage eventually forms bone. Most commonly, it affects the long bones in the leg, the pelvis, or scapula (shoulder blade).

Osteochondroma is the most common noncancerous bone growth. The lesion usually occurs during skeletal growth between the ages of 5 and 20 years.

What causes osteochondroma?

While the exact cause of osteochondroma is unknown, we know that one form of the disorder is inherited. There is also a noninherited form of the disorder.

What are the symptoms of osteochondroma?

The following are the most common symptoms of osteochondroma:

•    A hard, immobile, detectable mass that is painless
•    Lower-than-normal-height for age
•    Soreness of the adjacent muscles
•    One leg or arm may be longer than the other
•    Pressure or irritation with exercise

Often individuals with osteochondroma will have no symptoms at all.

How is osteochondroma diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for osteochondroma may include:

•    X-ray
•    Computed tomography scan (also called CT or CAT scan)
•    Magnetic resonance imaging (MRI)

How is osteochondroma treated?

Treatment for osteochondromas varies significantly depending on the size of the overgrowth and the symptoms of the individual. Treatment may include:

•    Surgery to remove the mass
•    Medications to control pain

If there is no sign of bone weakening or increased overgrowth, observation only may be suggested. Careful follow-up with your child’s doctor is recommended to monitor bone growth.