Fibrous dysplasia of bone.

Fibrous dysplasia of bone is a disorder of unknown etiology in which skeletal aberrations constitute the cardinal feature. The condition is often monostotic but may be polyostotic. The disorder may be accompanied by extraskeletal manifestations, such as abnormal cutaneous pigmentation and endocrinopathies, most commonly precocious puberty. Surgical therapy is recommended when bony deformities become substantial or when function is threatened.