Definition

Osteitis fibrosa is a complication of hyperparathyroidism, a condition in which overactive parathyroid glands cause certain bones to become abnormally weak and deformed.

Alternative Names

Osteitis fibrosa cystica; Hyperparathyroidism - osteitis fibrosa; Brown tumor of bone

Causes

The parathyroid glands are 4 tiny glands in the neck. These glands produce parathyroid hormone (PTH). PTH helps regulate calcium, phosphorus, and vitamin D levels in the blood and is important for healthy bones.

Too much parathyroid hormone (hyperparathyroidism) can lead to increased bone breakdown, which can cause bones to become weaker and more fragile. Many people with hyperparathyroidism eventually develop osteoporosis. Not all bones respond to PTH in the same way. Some develop abnormal areas where the bone is very soft and has almost no calcium in it. This is osteitis fibrosa.

In rare cases, parathyroid cancer causes osteitis fibrosa.

Osteitis fibrosa is now very rare in people who have hyperparathyroidism and good access to medical care. It is more common in people who develop hyperparathyroidism at a young age, or have untreated hyperparathyroidism for a long time.

Symptoms

Osteitis fibrosa may cause bone pain or tenderness. There may be fractures (breaks) in the arms, legs, or spine, or other bone problems.

Hyperparathyroidism itself may cause any of the following:

• Nausea
• Constipation
• Fatigue
• Frequent urination
• Weakness

Exams and Tests

Blood tests show a high level of calcium, parathyroid hormone, and alkaline phosphatase (a bone chemical). Phosphorus level in the blood may be low.

X-rays may show thin bones, fractures, bowing, and cysts. Teeth x-rays may also be abnormal.

A bone x-ray or bone density test 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.

Treatment

Most of the bone problems from osteitis fibrosa can be reversed with surgery to remove the abnormal parathyroid gland(s). Some people may choose not to have surgery, and instead be followed with blood tests and bone measurements.

If surgery is not possible, medicines can sometimes be used to lower the blood calcium level.

Possible Complications

Complications of osteitis fibrosa include any of the following:

• Bone fractures
• Deformities of bone
• Pain
• Problems due to hyperparathyroidism, such as kidney stones and kidney failure

When to Contact a Medical Professional

Contact your health care provider if you have bone pain, tenderness, or symptoms of hyperparathyroidism.

Prevention

Routine blood tests done during a medical checkup or for another health problem usually detect a high calcium level before severe damage is done.

References

Nadol JB, Quesnel AM. Otologic manifestations of systemic disease. In: Flint PW, Francis HW, Haughey BH, et al, eds. Cummings Otolaryngology: Head and Neck Surgery. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 151.

Patsch JM, Krestan CR. Metabolic and endocrine skeletal disease. In: Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM, eds. Grainger & Allison's Diagnostic Radiology. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 43.

Thakker RV. The parathyroid glands, hypercalcemia and hypocalcemia. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 227.

Walker MD, Bilezikian JP. Primary hyperparathyroidism. In: Robertson RP, ed. DeGroot's Endocrinology. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 54.