Fibrous dysplasia

What causes fibrous dysplasia?

The cause of fibrous dysplasia has been linked to a gene mutation that occurs after conception, in the early stages of fetal development. The mutation involves a gene that affects the cells that produce bone. People with fibrous dysplasia carry this mutation in some, but not all cells of their body. It is not well understood why the mutation occurs, but it is not inherited from a parent, nor can it be passed on from parents to children.

Last updated on 05-01-20

What part of the body does fibrous dysplasia typically affect?

Monostotic fibrous dysplasia is the least complicated type of fibrous dysplasia. It affects only one bone and most often occurs in the ribs, thigh bone, shin bone, or one of the facial bones. For the polyostotic form, the lesions often occur in younger patients and can involve numerous bones, sometimes more than half of the bones in the skeletal system. The most common sites in polyostotic fibrous dysplasia include the skull, face, thigh bone, shin bones, upper arm, pelvis, and ribs. Although when multiple bones are affected, they are often found on one side of the body, the disease does not "spread" from one bone to another. In fact, the pattern in which bones are involved is established very early in life and does not change with age.

Last updated on 05-01-20

Can bisphosphonate therapy stop the progression of fibrous dysplasia in adults?

To date, bisphosphonate therapy has not been shown to stop the progression of fibrous dysplasia in adults, however it does appear to decrease bone pain and improve the appearance of bone lesions on X-ray.

Last updated on 05-01-20

What is fibrous dysplasia?

Fibrous dysplasia is a skeletal disorder that is characterized by the replacement of normal bone with fibrous bone tissue. It may involve one bone (monostotic) or multiple bones (polyostotic). Fibrous dysplasia can affect any bone in the body. The most common sites are the bones in the skull and face, the long bones in the arms and legs, the pelvis, and the ribs. Though many people with this disorder do not have any symptoms, others may have bone pain, abnormally shaped bones (deformities), or an increased risk of fractures (broken bones). The problems a person experiences depend on which bones are affected, and may arise from compression and displacement of adjacent structures to the lesions. For example, the legs can be of different lengths, leading to a limp, the bones of the sinuses can be affected, leading to chronic sinus congestion or headache. This condition can occur alone or as part of a genetic disorder, such as McCune-Albright syndrome. While there is no cure for fibrous dysplasia, the symptoms can be treated. Medications known as bisphosphonates can reduce pain and surgery may be used to treat fractures or to correct misshapen bones.

Last updated on 05-01-20

Can fibrous dysplasia become cancerous?

Rarely, an affected area of bone can become cancerous. This rare complication typically affects only those who have had prior radiation therapy.

Last updated on 05-01-20

Where can I find more information on treatment for fibrous dysplasia?

The following resources contain information on treatment for fibrous dysplasia:

  • Children's Hospital Boston's web site has a fact sheet on fibrous dysplasia that includes information on treatment.
  • Medscape Reference provides detailed information on the treatment of this condition. This resource is aimed at healthcare professionals. You may need to register to view the article, but registration is free.
  • has general information on treatment for fibrous dysplasia.
  • lists trials that are studying or have studied treatments for Fibrous dysplasia.

Last updated on 05-01-20

How might fibrous dysplasia be treated?

Unfortunately, there is no cure for fibrous dysplasia. Treatment depends on the symptoms present.

  • Fractures often require surgery, but can sometimes be treated with casting or splints. Surgery is most appropriate in cases where fractures are likely to occur, or where bones have become misshapen. Surgery may also be used to relieve pain.
  • Medications known as bisphosphonates are also used to relieve bone pain.
  • Other healthy strategies such as physical activity and adequate intake of calcium, phosphorus, and vitamin D are also encouraged.

Radiation therapy is not recommended for patients with fibrous dysplasia because it is associated with an increased risk of cancerous transformation.

Careful, long-term follow-up to monitor fibrous dysplasia is advised.

Last updated on 05-01-20

Is the long-term use of bisphosphonates for treatment of fibrous dysplasia associated with an increased risk for bone fracture?

We were unable to find information regarding an increased risk for bone fracture in people with fibrous dysplasia who undergo short or long-term treatment with bisphosphonates. Rare but serious complications have been described in patients who received bisphosphonate therapy for other indications (e.g., osteoporosis). You can learn more about bisphosphonate drugs including reported side effects, at the following link to

So far studies investigating the use of bisphosphonate therapies for treatment of fibrous dysplasia have been small and uncontrolled. Further information regarding the benefits and complications associated with bisphosphonate therapy for treatment of fibrous dysplasia is likely on the horizon. The National Institute of Dental and Craniofacial Research at the National Institutes of Health completed a three year, phase 2, clinical trial of Fosamax (Alendronate) for treatment of fibrous dysplasia. The clinical trial was entitled 'Alendronate to Treat Polyostotic Fibrous Dysplasia and McCune- Albright Syndrome.' Click here to view the study information. In our search, we were unable to find published results from the trial. You can contact the National Library of Medicine (NLM) Customer Service for further assistance in searching the medical literature for published results.

National Library of Medicine Customer Service
Toll-free: 888-346-3656

In addition, there is an ongoing clinical trial in Europe, entitled Effect of Risedronate on Bone Morbidity in Fibrous Dysplasia of Bone (PROFIDYS), that is investigating the efficacy of oral bisphosphonate to decrease bone pain and improve radiological appearance of fibrous dysplasia. Click on the title above to learn more.

Last updated on 05-01-20

Where To Start

children's hospital boston - Fibrous dysplasia

The Children's Hospital Boston's Web site has an information page on this topic. Click on the link above to view this information page.

Last updated on 04-27-20

Name: The MAGIC Foundation 4200 Cantera Dr. #106
Warrenville, IL, 60555, United States
Phone: 630-836-8200 Toll Free: 800-362-4423 Fax : 630-836-8181 Email: Url:
Name: Fibrous Dysplasia Foundation, Inc. 2885 Sanford Ave. SW #40754
Grandville, MI, 49418, United States
Email: Url:
Name: The Limb Preservation Foundation 925 S Niagara Street Suite 610
Denver, CO, 80224,
Phone: (303) 429-0688 Email: Url:

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