Health Information

Fibrous Dysplasia

What is fibrous dysplasia?

Fibrous dysplasia is a chronic disorder in which bone expands due to abnormal development of fibrous tissue, often resulting 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 between males and females.

What causes fibrous dysplasia?


The exact cause of fibrous dysplasia is not known, but 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, but it is not known to be an inherited disorder.

What causes fibrous dysplasia?

The exact cause of fibrous dysplasia is not known, but 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, but it is not known to be an inherited disorder.

Treatment for fibrous dysplasia:

Specific treatment for fibrous dysplasia will be determined by your physician based on:
  • your age, overall health, and medical history
  • extent of the condition
  • your tolerance for specific medications, procedures, or therapies
  • expectations for the course of the condition
  • your opinion or preference