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
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:
Tibia (shin bone)
bone of the upper arm)
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 cafe-au-lait spots.
Fibrous dysplasia usually occurs in children and young adults, and
is found equally between males and females.