Nonossifying Fibroma

  • What is nonossifying fibroma?

    Nonossifying fibromas are the most common benign bone tumors in children. Made up mainly of fibrous tissue, nonossifying fibromas are not aggressive, do not spread or become malignant (cancerous).

    Nonossifying fibromas often have no symptoms; many children do not even know they have this benign tumor until it is discovered — by chance — on an X-ray for another issue. Nonossifying fibromas usually occur in the femur (thigh bone) or tibia (shin bone), but may also occur in the upper extremities of the arms and hands. These benign tumors occur twice as often in boys as girls.

    Experts estimate 30-40 percent of people younger than 20 years old have at least one nonossifying fibroma. Most will require no treatment, as the nonossifying fibroma will resolve on its own when the child is fully grown.

  • Causes

    The cause of nonossifying fibroma is unknown. Researchers have not found evidence linking these benign tumors to genetics, the environment or injuries.

  • Signs and symptoms

    Most children with nonossifying fibroma will experience no symptoms. Those who do experience symptoms report:

    • Mild swelling or soreness in the affected area.
    • A dull ache in the affected area, even during periods of inactivity.
    • A broken bone that is later discovered to be caused, at least partly, by the nonossifying fibroma that has weakened the overall strength of the bone. Fractures are more likely when the nonossifying fibroma is larger.
  • Testing and diagnosis

    At The Children’s Hospital of Philadelphia (CHOP), your child's diagnostic evaluation begins with a thorough medical history and physical examination of your child.

    Clinical experts use a variety of diagnostic tests to diagnose nonossifying fibroma, including:

    • X-rays, which produce images of bones and internal organs on film.
    • Magnetic resonance imaging (MRI), which uses a combination or large magnets, radiofrequencies and a computer to produce detailed images of organs and structures within the body.
    • 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.
  • Treatments

    Most nonossifying fibromas require no treatment. They usually resolve on their own when your child’s bones stop growing.

    In some circumstances, treatment may be recommended to avoid fracture. These include:

    • When several nonossifying fibromas are present.
    • If your child is very active or athletic.
    • If your child has already experienced a bone fracture or the tumor has substantially weakened his or her bones.

    If surgery is necessary, intralesional curettage is generally the chosen treatment. Curettage involves scraping out the bone to completely remove the tumor and filling the space with bone grafting material.

    If your child has already sustained a broken bone, physicians may use surgically placed metal rods and pins to strengthen the bone and allow your child to become active sooner after surgery.

    While surgery for nonossifying fibroma is highly effective, we understand that any surgery can be a stressful experience for your child and family. 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. See safety in surgery for details about safety protocols at The Children's Hospital of Philadelphia.

  • Follow-up care

    At The Children's Hospital of Philadelphia, we offer ongoing support and services for your child and family 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.

    If your child had surgical treatment for nonossifying fibroma, he or she will return for check-ups one to two weeks after surgery, then again at three months, six months and one year post-surgery.

    Most patients return to normal activity within three to six months after surgery, though timing may vary depending on the size of the tumor, the type of bone graft used and how quickly your child heals.

  • Outlook

    Outcomes for children treated at CHOP for nonossifying fibroma have been very good.

    Regular follow-up is recommended to ensure the tumor is not growing back.

Reviewed by John P. Dormans, MD, FACS on May 19, 2014