Fibrous Dysplasia

Fibrous dysplasia makes your body grow weaker, fibrous tissue in your bones instead of healthy bone tissue. It can affect any bone in your body. Having fibrous dysplasia makes you more likely to experience bone fractures throughout your life.


What is fibrous dysplasia?

Fibrous dysplasia is a rare bone condition. It makes your body grow weaker, fibrous tissue instead of healthy bone tissue. It can also affect the shape of your bones as they grow. Healthcare providers refer to this kind of growth as dysplastic, which is where fibrous dysplasia gets its name — fibrous growth that affects the strength and shape of your bones.

Fibrous dysplasia can make your bones fragile and more susceptible to bone fractures (broken bones). It can affect any bone in your body, but most commonly affects your:

The abnormal tissue from fibrous dysplasia is almost always benign, which means it isn’t a symptom of (and doesn’t cause) cancer.

Types of fibrous dysplasia

Healthcare providers classify fibrous dysplasia based on how many of your bones it affects:

  • Monostotic fibrous dysplasia affects only one bone.
  • Polyostotic fibrous dysplasia affects multiple bones.

How common is it?

Fibrous dysplasia is rare. It’s hard for experts to estimate how many people have it because people with fibrous dysplasia don’t get diagnosed unless they experience a fracture or other symptoms.


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Symptoms and Causes

What are fibrous dysplasia symptoms?

Some people with fibrous dysplasia never notice symptoms. Which symptoms you experience depends on a few factors, including:

  • How many of your bones are affected.
  • Where in your body the affected bones are.
  • If you’ve experienced a bone fracture.

The most common fibrous dysplasia symptoms include:

Some fibrous dysplasia symptoms might seem unrelated to your bones. If the bones in your face are affected, you might experience:

What causes fibrous dysplasia?

A genetic mutation causes fibrous dysplasia. Specifically, a mutation (change) on chromosome 20, one gene that’s in charge of your bone formation and growth.

Experts aren’t sure what causes the mutation that leads to fibrous dysplasia.


What are complications of fibrous dysplasia?

The most common complication of fibrous dysplasia is making you more likely to experience a bone fracture.

If the fibrous bone tissue affects nerves around your eyes or ears, fibrous dysplasia can affect your vision or cause hearing impairment.

Diagnosis and Tests

How is fibrous dysplasia diagnosed?

A healthcare provider will diagnose fibrous dysplasia with a physical exam and tests. If you’re experiencing pain, your provider will examine that part of your body and the area around it. Tell your provider about any symptoms you’re experiencing and when you first noticed them.

What tests are done to diagnose fibrous dysplasia?

Your provider will likely need a few tests to diagnose fibrous dysplasia, including:

  • Imaging tests: X-rays will show the shape of your bones and any fibrous tissue. They’ll also show if your bones are fractured. You might also need an MRI (magnetic resonance imagining or a CT (computed tomography) scan.
  • Lab tests: Blood tests and urine tests will show increased levels of enzymes in your blood or pee (urine), which might mean the fibrous tissue is growing in your body.
  • Biopsy: Your provider might use a biopsy to remove a sample of the fibrous tissue or your healthy bone tissue for testing.


Management and Treatment

How is fibrous dysplasia treated?

How providers treat fibrous dysplasia depends on how severe your symptoms are. The most common fibrous dysplasia treatments include:

  • Observation: You might not need any treatment other than follow-up appointments with your provider. They’ll monitor any changes in your bone health.
  • Medication: Your provider might prescribe medication that can strengthen your bones and help prevent fractures.
  • Bracing: Wearing a brace can support your bones and help them grow correctly.
  • Surgery: You might need surgery if the fibrous growths are causing complications inside your body or haven’t responded to other treatments. You might need surgery if you experience a bone fracture. Some people with fibrous dysplasia need a bone graft. Your provider or surgeon will tell you what to expect and how long it will take to recover.


Can fibrous dysplasia be prevented?

There’s no way to prevent fibrous dysplasia. Even though experts know which genetic mutation causes fibrous dysplasia, they aren’t sure how to prevent it or even why it happens.

Outlook / Prognosis

What can I expect?

Every case of fibrous dysplasia is unique. Because it can affect any bone in your body — and because the symptoms vary so widely — it’s impossible to say how any one person’s experience with it will compare to another’s.

Fibrous dysplasia doesn’t spread to other bones once it’s established.

Living With

When should I see my healthcare provider?

Visit a healthcare provider if you notice any symptoms of fibrous dysplasia like pain or café au lait spots. Talk to your provider if you feel like your symptoms are worsening or aren’t responding to your treatments.

When should I go to the ER?

Go to the emergency room if you experience a trauma like a serious fall or car accident, or if you think you have a bone fracture.

What questions should I ask my healthcare provider?

  • Which bones are affected?
  • Which treatments will I need?
  • Will I need surgery?
  • How can I prevent bone fractures?

Additional Common Questions

Is fibrous dysplasia a tumor?

Yes, fibrous dysplasia growths are tumors. “Tumor” is the medical word that means any mass of abnormal cells in your body. But that doesn’t mean you have (or will develop) cancer. Fibrous dysplasia rarely causes cancer.

Is fibrous dysplasia serious?

Fibrous dysplasia can be serious because it can make you more likely to experience a bone fracture. It affects everyone differently, so there’s no easy answer to if it will or won’t have a big impact on your life. Talk to your provider about your risk and if there are any activities you should avoid.

A note from Cleveland Clinic

Fibrous dysplasia is a condition that makes weaker, fibrous tissue grow on your bones. It’s caused by a genetic mutation that you can’t prevent, and it’s extremely rare for fibrous dysplasia to be a symptom of (or cause) cancer. Your healthcare provider will help you find ways to treat your affected bones and prevent fractures.

Medically Reviewed

Last reviewed on 09/25/2023.

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