Osteitis fibrosa is a complication of hyperparathyroidism (excess parathryroid hormone production) in which bone becomes softened and deformed and may develop cysts.
Causes, incidence, and risk factors
There are four parathyroid glands in the neck. They produce parathyroid hormone, which helps control calcium levels in the body. Parathyroid hormone increases bone “turnover” (metabolism) and may soften it.
Sometimes the parathyroid glands produce too much parathyroid hormone (hyperparathyroidism). In these cases, one gland may develop a growth (80% of cases), or all 4 glands may enlarge (15% of cases). Rarely, parathyroid cancer may cause the condition.
Hyperparathyroidism is most common in women over 60. Genetic changes cause the condition, and it sometimes runs in families. Neck radiation increases the likelihood of developing this disorder.
Before 1950, about half of people diagnosed with hyperparathyroidism had osteitis fibrosa. Now it is uncommon - occurring in fewer than 10% of people with hyperparathyroidism - because patients with hyperparathyroidism are diagnosed earlier and have milder elevations of calcium.
People with severe hyperparathyroidism, or those who have parathyroid cancer, are more at risk for developing osteitis fibrosa.
Osteitis fibrosa cystica may cause bone pain or tenderness. There may be fractures (breaks) in the arms, legs, or spine, or deformities (bowing of the bones). Hyperparathyroidism itself may cause Kidney stones or problems, nausea or Constipation, or fatigue and weakness.
Signs and tests
Blood tests show a high level of calcium and alkaline phosphatase (a bone chemical). Phosphorus may be low. The level of parathyroid hormone is elevated.
X-rays may show thin bones, fractures, bowing, and cysts. The cysts may be filled with clear fluid or filled with material (“brown tumors”). The skull may look like “ground glass” or “salt and pepper.” The outer part of bones may be eroded; the most sensitive area to check is the fingers. Teeth X-rays may also be abnormal.
The main treatment for hyperparathyroidism is surgery to remove the abnormal parathyroid gland(s).
Newer techniques use radioactive tracers and rapid parathyroid hormone blood tests to make the surgery quicker and easier. If surgery is not possible, drugs can sometimes be used to lower calcium levels.
Most of the bone problems of osteitis fibrosa are usually reversible with surgery.
The complications of osteitis fibrosa include bone fractures, pain, and deformities. There may be other problems stemming from the hyperparathyroidism itself, such as Kidney stones and Kidney failure.
Calling your health care provider
A physician should be called if you notice bone pain, tenderness, or if you have a fracture or any of the symptoms of hyperparathyroidism.
Today, most people have blood tests from time to time. Therefore, high calcium levels are usually found before any severe damage is done.
A bone X-ray may be done. People with hyperparathyroidism are more likely to have osteopenia (thin bones) or Osteoporosis (very thin bones) than to have full-blown osteitis fibrosa.
Most patients with hyperparathyroidism have no symptoms, and many can be followed with blood tests and bone measurements. Others are advised to have surgery to prevent further problems.
by Brenda A. Kuper, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.