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Fibrous Dysplasia

What is fibrous dysplasia?

Fibrous dysplasia is a chronic disorder in which an abnormal development of fibrous tissue causes bones to expand. It often results in one or more, of the following:

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

Any bone can be affected. More than one bone can be affected at any one time, and, when multiple bones are affected, it is not unusual for them to all be on one side of the body. However, fibrous dysplasia does not spread from one bone to another. The most commonly affected bones include the following:

  • Femur (thighbone)
  • Tibia (shin bone)
  • Ribs
  • Skull
  • Facial bones
  • Humerus (the bone of the upper arm)
  • Pelvis
  • Vertebrae in the spine (less often)

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

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

What causes fibrous dysplasia?

The exact cause of fibrous dysplasia is not known. It is believed to be due to a chemical irregularity in a specific bone protein. This bone protein abnormality may be due to a gene mutation present at birth, although it is not known to be an inherited disorder.

What are the symptoms of fibrous dysplasia?

The following are the most common symptoms for fibrous dysplasia. However, each person may experience symptoms differently. Symptoms may include:

  • A waddling walk
  • Bone pain (as a consequence of the expanding fibrous tissue in the bone)
  • Bone deformity
  • Bone fractures
  • Scoliosis (a sideways curve of the spine)

The symptoms of fibrous dysplasia may look like other bone disorders or medical problems. Always consult your doctor for a diagnosis.

How is fibrous dysplasia diagnosed?

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

  • X-ray. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
  • Biopsy. A procedure in which tissue samples are removed (with a needle or during surgery) from the body for exam under a microscope. It’s done to determine if cancer or other abnormal cells are present; to remove tissue from the affected bone.
  • Computed tomography scan (also called a CT or CAT scan). A diagnostic imaging 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.
  • Blood tests

How is fibrous dysplasia treated?

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

  • Your age, overall health, and medical history
  • Extent of the disease
  • Your tolerance for specific medications, procedures, or therapies
  • Expectations for the course of the disease
  • Your opinion or preference

Surgical treatment may include the following procedures:

  • Removal of affected bone, followed by bone grafting. This is a surgical procedure in which healthy bone is transplanted from another part of the body into the affected area.
  • Removal of bone wedge
  • Placement of a rod down the shaft of the bone

Other treatment may include:

  • Medication
  • Pain management
  • Physical therapy

Key points about fibrous dysplasia

Fibrous dysplasia is a chronic disorder in which bone expands due to abnormal development of fibrous tissue. 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 inherited.
  • Symptoms may include bone pain and deformity, a waddling walk and scoliosis.
  • Treatment may include surgery, medication, pain management, or physical therapy.

Next steps

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

  • 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 names of new medicines, treatments, or tests, and any new instructions your provider gives you.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.