Overview

Parathyroid cancer is a cancerous (malignant) growth in a parathyroid gland.

The parathyroid glands are responsible for controlling the calcium in the body. There are four parathyroid glands, two on each lobe of the thyroid gland. They are located at the base of the neck.
Parathyroid cancer is an extremely rare type of cancer. Men and women are equally affected. It usually occurs in people older than 30.
The cause of parathyroid cancer is unknown. People with multiple endocrine neoplasia type I have an increased risk for this disease. People who had head or neck radiation may also be at increased risk. Such radiation exposure, however, is more often connected with thyroid cancer.

Symptoms of parathyroid cancer are primarily caused by high levels of calcium in the blood (hypercalcemia), and may affect various parts of the body. They include:

• Abnormal fractures
• Bone pain
• Constipation
• Fatigue
• Frequent thirst
• Frequent urination
• Kidney stones
• Muscle weakness
• Nausea
• Poor appetite
• Vomiting

Parathyroid cancer is extremely hard to diagnose.
Your doctor will perform a physical exam and ask about your medical history.
In about half of all cases, feeling the neck with the hands (palpation) can reveal a cancerous parathyroid tumor.
Cancerous parathyroid tumors tend to produce very high amounts of parathyroid hormone (PTH). Tests may include:

• Serum calcium (levels higher than 14 mg/dL are suspicious)
• Serum PTH (levels that are more than twice than normal may indicate cancer)

Before surgery, you will undergo a special radioactive scan of the parathyroid glands. The scan is called the sestamibi scan. You may also have a neck ultrasound.

The following treatments may be used to correct hypercalcemia due to parathyroid cancer:

• A drug that lowers levels of calcium in the blood (gallium nitrate)
• A natural hormone produced by the body that helps control calcium levels (calcitonin)
• Drugs that stop the destruction and reabsorption of bones into the body, such as pamidronate or etidronate (bisphosphonates)
• Fluids through a vein (IV fluids)

Surgery is the recommended treatment for parathyroid cancer. Very often, it is impossible to know whether a parathyroid tumor is cancerous or not. Your doctor may recommend surgery even without a confirmed diagnosis.
If tests before the surgery can find the suspicious gland, surgery may be done on one side of the neck (unilateral). If it is not possible to find the problem gland before surgery, the surgeon will look at both sides of your neck.