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.

Parathyroid cancer is a slow growing cancer. It is also extremely hard to diagnose.

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

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

Your doctor will perform a physical exam and ask about your medical history.

In about half of all cases, palpation (feeling with hands) can reveal a cancerous parathyroid tumor.

Cancerous parathyroid tumors tend to produce very high amounts of parathyroid hormone (PTH). Tests may include:

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

Prior to 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.