What is osteochondroma?

Osteochondroma is the most common benign bone tumor in children. Because an osteochondroma often displays no symptoms, the tumor may only be discovered when a child notices a bump, or reports pain. For some children, the osteochondroma may never be discovered.

An osteochondroma looks like a bony projection on the external surface of a bone, like a bony mushroom on a stalk, usually near a growth plate area. It can occur in any bone but is seen most often around the knee or upper arm.

This tumor generally grows with the child and stops growing once the child completes puberty. Most osteochondromas are diagnosed in patients younger than 20 years old and are more likely to affect boys than girls.


The cause of osteochondroma is unknown, but there is a theory that this tumor may be the result of genetic abnormalities. Clinicians and scientists at Children’s Hospital of Philadelphia (CHOP) are currently studying this condition and its origins.

Signs and symptoms

In most cases, an osteochondroma causes no symptoms. However, depending of the location and size of the bony growth, some can cause:

  • Pain
  • A visible bump under the skin
  • Deformity
  • Growth disturbances
  • Nerve compression causing weakness of muscles

Testing and diagnosis

At Children’s Hospital of Philadelphia, our clinical experts use a variety of diagnostic tests to diagnose osteochondroma in children, including:

  • X-rays, which produce images of bones on film. 
  • Magnetic resonance imaging (MRI), which uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs, soft tissues, muscles, ligaments and other structures within the body. Your child is exposed to no radiation during an MRI.
  • Computed tomography (CT) scan, which uses a combination of X-rays and computer technology to produce cross-sectional images ("slices") of the body.
  • EOS imaging, an imaging technology that creates 3-dimensional models from two planar images. Unlike a CT scan, EOS images are taken while the child is in an upright or standing position, enabling improved diagnosis due to weight-bearing positioning.


There are many treatment options available for bone and soft tissue tumors, and some children will need a combination of these therapies. At CHOP, experts at the Bone and Soft Tissue Tumor Program take a team approach to treatment. Orthopaedic and other specialists collaborate to provide your child with individualized care and the best possible outcomes.

Our program is led by Kristy L. Weber, MD, and Alexandre Arkader, MD, nationally renowned surgeons who specialize in treating bone and soft tissues tumors, limb-sparing surgery and reconstructive surgery.

In most cases of solitary osteochondroma, once the diagnosis is made by your child’s physician no further action is needed. These tumors will stop growing and remain stable when your child’s bones stop growing.

If your child’s osteochondroma is causing pain, restricting movement of a joint, or affecting growth, surgical removal may be indicated.

Treatment for osteochondroma is generally a simple surgical removal of the lesion from the bone surface. The surgeon will be careful not to harm your child’s growth plate to ensure normal physical development after the operation.

Surgical safety

Though surgery for osteochondroma is highly effective, we understand that any surgery can be a stressful experience for children and families. At CHOP, we offer a wealth of resources about how to prepare your child for surgery and what to expect during surgery

Additionally, we employ numerous best practices before, during and after surgery to decrease the risk of infection and increase positive outcomes. For more details about safety protocols at Children's Hospital of Philadelphia, see safety in surgery.

Follow-up care

After surgery for osteochondroma, most children can resume normal activities. However, in some cases, such as when the tumor was on a weight-bearing bone, your child’s physician may recommend restricted activity or use of crutches for a short period of time for your child to allow proper healing.

If the tumor did not cause bone deformity or compromise the growth plate, your child will need only limited follow-up. If there were complications from the tumor, your child may need continued monitoring.

At Children's Hospital of Philadelphia, we offer ongoing support and services for patients and families at our Main Campus and throughout our CHOP Care Network. Our team is committed to partnering with parents and referring physicians to provide the most current, comprehensive and specialized care possible for your child.


The likelihood of your child’s osteochondroma recurring is extremely low — although more common if it is removed at a young age — and the outcomes for children treated for this condition is excellent.

Reviewed by Kristy L. Weber, MD, FACS, Alexandre Arkader, MD

Providers Who Treat Osteochondroma

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