Massachusetts General Hospital

Osteochondroma

What is osteochondroma?

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 benign (noncancerous) bone growth. The lesion usually occurs during skeletal growth between the ages of 10 and 30 years. It affects males and females equally.

What causes osteochondroma?

While the exact cause of osteochondroma is not known, there is a genetic link, indicating that there is a form of the disorder that 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. However, each individual may experience symptoms differently. Symptoms may include:

• 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.

The symptoms of osteochondroma may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.

How is osteochondroma diagnosed?

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

• X-ray. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.

• Computed tomography scan (also called CT or CAT scan). A noninvasive diagnostic procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.

• Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.

Treatment for osteochondroma

Specific treatment for osteochondroma will be determined by your doctor based on:

• Your age, overall health, and medical history

• Extent of the disease

• Location of the osteochondroma 

• Your tolerance for specific medications, procedures, and therapies

• Expectation for the course of the disease

• Your opinion or preference

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 a doctor to monitor bone growth may be recommended.