The center for Endocrine Tumors and disorders treats a wide variety of rare bone disorders including Pagets bone disease, Fibrous Dysplasia, Rickets, hypophosphatemia, and bone metastases from cancer.
Paget’s disease of the bone is a chronic condition that upsets the normal biological process of the bones – the normal remodeling process of old bones breaking down and being replaced by new bone is disrupted. It is more common in older people, and slightly more men than women have it. The body forms new enlarged and deformed bones that over time grow weak, which can lead to bone pain, arthritis, hearing loss, progressive deformities and fractures.
Symptoms and risk factors
The disease may affect multiple members of a family which is the case in about 20% of individuals. A variety of gene abnormalities have been found in these families. Another factor is probably a complication of a measles virus infection in the distant past.
Some patients will have only one affected bone, while others may have two, three or more. The disease does not usually spread to unaffected bones. Most people with Paget’s disease have no symptoms. They may never know they have the disease until it progresses and complications develop.
When it occurs, pain may be constant, aching and deep and may be most severe at night. Headaches and hearing loss may occur when the disease affects the skull. Pressure on nerves may occur when the skull or spine is affected. Damage to cartilage of joints adjacent to the affected bone may lead to arthritis, and hip pain may occur when the pelvis or thighbone is involved. In advanced cases, deformities of bone can cause an increased head size, bowing of a limb or curvature of the spine. Sometimes, symptoms are confused with arthritis or other disorders.
To help diagnose the disease, a physician may use an x-ray, an alkaline phosphatase blood test and/or a bone scan.
The disease can be best treated by a single intravenous dose of zoledronic acid which can stop disease activity for more than six years.
Fibrous dysplasia is a bone disorder in which fibrous tissue develops in place of normal bone. It is an uncommon bone disease which is caused by an abnormal gene in one or more bones which likely develops prior to birth of a child.
However, it is not hereditary and therefore not transmitted from a parent or passed on to the children of the affected individual.
As the bone grows, the softer, fibrous tissue expands, weakening the bone. The abnormality causes uneven growth, brittleness and deformity in affected bones. Fibrous dysplasia is found equally in males and females and does not appear to vary in incidence among the races.
Symptoms and risk factors
Mild cases usually cause no signs and symptoms. More serious cases may result in bone pain, deformity and fractures. 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.
In some patients a variety of hormonal problems may develop including precocious puberty, hyperthyroidism, and excess cortisone or growth hormone secretion. These conditions can be corrected. These individuals can have a number of birth marks on the skin. The bone disorder plus hormonal disturbances is termed McCune-Albright Syndrome.
Physicians may use an x-ray, MRI or CT scan to detect abnormal bone tissue. A bone scan may also be ordered.
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 corridor to reach the lesions.
In cases where fibrous dysplasia causes cranial nerve impingement, microvascular decompression is recommended.
The most common cancers that spread to the bone in advanced disease are Breast and Prostate.
Once cancer cells settle in the bone, they begin to interfere with the normal health and strength of the bones, leading to bone pain, fracture, or other complications that can significantly impair a person’s health. An x-ray is used to determine where the cancer has spread. Treatment depends on where and how wide the cancer has spread, health of the bones, and prior therapy.
Breast Cancer Bone Metastases:
- If x-rays show that cancer exists in only one location, radiation therapy may be the only treatment needed at that time.
- If cancer cells show up in several parts of the skeleton, hormonal or chemotherapy might be the best approach. Radioactive drugs or bisphosphonate drugs [link to medications, bisphosphonates] may also be effective. The latter has been shown in studies to reduce pain, skeletal complications and elevated calcium in the blood.
- If the bone has thinned to the point that a fracture is likely, an orthopedic procedure may be necessary to support a bone and prevent a break.
Prostate Cancer Bone Metastases:
Generally treated by testosterone reduction either through medication or by surgical removal of the testes.