Saint John's Health Center
Fibrous Dysplasia

Overview

Fibrous dysplasia is a bone disorder in which fibrous tissue develops in place of normal bone.  As the bone grows, the softer, fibrous tissue expands, weakening the bone.  The abnormality causes uneven growth, brittleness and deformity in affected bones.

Any bone can be affected by fibrous dysplasia.  Some patients have only one bone involved and other have numerous bones affected.  The most common sites of disease are the thigh, shin, ribs, skull, facial bones, upper arm and pelvis.  Fibrous dysplasia is not a disease that spreads from one bone to another. 

Diagnosis & Symptoms

Physicians may use an x-ray, MRI or CT Scan to detect abnormal bone tissue. A bone scan may also be ordered.

Mild cases usually cause no signs and symptoms. More serious cases may result in bone pain, deformity and fractures. It is usually diagnosed in children and young adults. If the disease involves more than one bone, it is more likely to produce problems before the age of 10 years. Fibrous dysplasia is found equally in males and females and does not appear to vary in incidence among the races. 

Treatment

If a patient does not have any symptoms of fibrous dysplasia, treatment may consist of long-term observation by a physician. For patients who do exhibit symptoms, medications or surgery may be recommended.

Drugs being used to treat osteoporosis are used to treat fibrous dysplasia they help to prevent breakdown of bone. Surgical treatment for fibrous dysplasia involves removal of the affected bone, followed by a bone graft from another part of the body. For people who have fibrous dysplasia of the skull base, surgeons can use the expanded endonasal approach (EEA). The EEA is a minimally invasive procedure that uses a nostril as a natural corrider to reach the lesions.

In cases where fibrous dysplasia causes cranial nerve microvascular decompression is recommended.