Bone Health

Fibrous Dysplasia

What is fibrous dysplasia?

Fibrous dysplasia is a benign (non-cancer) chronic problem in which scar-like tissue grows in place of normal bone. It often results in 1 or more of these:

  • Bone deformity
  • Brittle bones
  • Pain
  • Uneven growth of bones

Any bone can be affected. More than 1 bone can be affected at any 1 time. When multiple bones are affected, it is often bones on 1 side of the body. However, fibrous dysplasia does not spread from one bone to another. The most commonly affected bones include:

  • Facial bones
  • Pelvis
  • Ribs
  • Shinbone (tibia)
  • Skull
  • Thighbone (femur)
  • Upper arm bone (humerus) 
  • Vertebrae in the spine

Some people develop hormonal problems and a condition called McCune-Albright syndrome. McCune-Albright syndrome is another form of fibrous dysplasia. It causes different symptoms, such as early start of puberty and skin spots, called café-au-lait spots.

Fibrous dysplasia usually occurs in children ages 3 to 15. It is sometimes not diagnosed until adulthood. It is found equally in men and women and in all races.

What causes fibrous dysplasia?

The exact cause of fibrous dysplasia is not known. It is believed to be due to a chemical defect in a specific bone protein. This defect may be due to a gene mutation that a baby has at birth. But the condition is not known to be passed down in families.

What are the symptoms of fibrous dysplasia?

Below are the most common symptoms for fibrous dysplasia. But each person may experience symptoms differently. Symptoms may include:

  • A waddling walk
  • Bone deformity
  • Bone fractures
  • Bone pain (which happens when the fibrous tissue expands in the bone)
  • Scoliosis (a sideways curve of the spine)
  • Hormonal disturbances
  • Skin discoloration

The symptoms of fibrous dysplasia may look like other medical problems. Always talk with your healthcare provider for a diagnosis.

How is fibrous dysplasia diagnosed?

In addition to a complete medical history and physical exam, other tests may include:

  • Biopsy. A test in which tissue samples are removed from the body and looked at under a microscope. It can help determine if cancer or other abnormal cells are present. It can also be done to remove tissue from the affected bone.
  • Bone scan. You may have a bone scan. This is done to look for growths in all of your bones. During this test, a very small amount of radioactive dye is injected into your body by IV.
  • Lab tests. When fibrous dysplasia lesions are actively growing, blood and urine tests may show elevated levels of certain enzymes and amino acids in the body.
  • Other imaging tests. You may need an MRI or CT scan to assess the affected bones more. 
  • X-ray. This is a test that makes images of internal tissues, bones, and organs onto film.

How is fibrous dysplasia treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

Treatment with surgery may include:

  • Placement of a rod down the shaft of the bone
  • Removal of affected bone, followed by bone grafting
  • Removal of bone wedge

Other treatment may include:

  • Medicines
  • Pain management
  • Physical therapy

Key points about fibrous dysplasia

  • Fibrous dysplasia is a chronic disorder in which scar-like tissue grows in place of normal bone. Any bone can be affected.
  • Fibrous dysplasia usually occurs in children ages 3 to 15, but it sometimes is not diagnosed until adulthood.
  • The exact cause of fibrous dysplasia is not known, but it is not passed down through families.
  • Symptoms may include bone pain and deformity, a waddling walk, and scoliosis.
  • Treatment may include surgery, medicines, pain management, or physical therapy.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
  • Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.
  • Ask if your condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if you do not take the medicine or have the test or procedure.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your healthcare provider if you have questions.

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