Fibrous Dysplasia

  • What is fibrous dysplasia?

    Fibrous dysplasia is a bone disease that destroys normal bone and replaces it with fibrous bone tissue. This tissue is not hard like normal bone, but is soft and stringy, making it more fragile and prone to break.

    Fractures occur in about 50 percent of patients with fibrous dysplasia. One or more bones can be affected and most often it is a long bone, such as the femur (thigh bone).

    Patients with fibrous dysplasia have an increased risk of developing malignant tumors such as osteosarcoma, fibrosarcoma, chondrosarcoma and malignant fibrous histiocytoma. However, that increased risk is very low — only about 1 percent of cases.

    Fibrous dysplasia occurs in childhood, usually between the ages of 3 and 15. Boys are more often diagnosed with fibrous dysplasia than girls, except one specific type of fibrous dysplasia — McCune-Albright syndrome — which is more common in girls.

    There are two forms of fibrous dysplasia:  

    • Monostotic, which is active while the child is growing but often becomes inactive after puberty
    • Polyostotic, which remains active throughout a person’s life

    Fibrous dysplasia is also known as inflammatory fibrous hyperplasia or idiopathic fibrous hyperplasia.

  • Causes

    The cause of fibrous dysplasia is unknown, but researchers have ruled out hereditary origins.

  • Signs and symptoms

    Symptoms of fibrous dysplasia can include:

    • Bone fractures or bone deformities
    • Bone pain
    • Bone sores or lesions which may stop when the child reaches puberty
    • Difficulty walking
    • Endocrine gland problems
    • Unusual skin color (lighter and darker spots on the skin)
  • 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 fibrous dysplasia, including:

    • Radioisotope bone scan, which can help locate an area of abnormal bone growth. 
    • Magnetic resonance imaging (MRI), which uses a combination of 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.
    • X-rays, which produce images of bones and internal organs on film.
    • 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.
    • Endocrine screening, which tests hormone levels.
  • Treatments

    At CHOP, treatment of fibrous dysplasia is based on your child’s symptoms and results of diagnostic testing.

    Non-surgical treatment

    In some cases, fibrous dysplasia can be treated with a class of drugs called bisphosphonates, which prevent bone loss and can reduce pain.

    Surgical treatment

    If the thigh bone is fractured due to fibrous dysplasia, surgical treatment is almost always necessary.

    Though surgery for fibrous dysplasia 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.

    Surgical treatment for fibrous dysplasia consists of:

    • Intralesional curettage, which involves scraping out the bone to completely remove the tumor and filling the space with material such as methyl methacrylate cement or diluted phenol.
    • Intramedullary nails, which are metal rods placed in a bone to provide additional support to make activity possible earlier and encourage healing.

    After surgery for fibrous dysplasia, your child should expect to stay overnight in the Hospital.

  • 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 fibrous dysplasia, he or she will return for check-ups one to two weeks after surgery, then again at three months, six months, one year and two years post-surgery.

    Follow-up is important in fibrous dysplasia to prevent deformities as a result of the disease and check for recurrence. In 50 percent of cases, fibrous dysplasia will recur.

    During follow-up visits, your child’s physician will likely perform a physical exam and order X-rays of the affected area until your child reaches skeletal maturity. Your child may also be referred to an endocrinologist for periodic testing of any thyroid abnormalities.

    If your child is diagnosed with McCune-Albright syndrome, a subset of fibrous dysplasia, your child will also be monitored for any spine curvatures such as scoliosis.

  • Outlook

    Outcomes for children treated for fibrous dysplasia at CHOP have been excellent. Because the disease often recurs, continued clinical monitoring is extremely helpful in long-term management of the condition.

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