Parathyroid cancer is a cancerous (malignant ) growth in a parathyroid gland.
The parathyroid glands control the calcium level in the body. There are four parathyroid glands, two on top of each lobe of the thyroid gland, which is located at the base of the neck.
Parathyroid cancer is a very 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 a genetic condition called multiple endocrine neoplasia type I have an increased risk of this disease. People who had head or neck radiation may also be at increased risk. Such radiation exposure, however, is more likely to cause thyroid cancer.
Symptoms of parathyroid cancer are mainly caused by a high level of calcium in the blood (hypercalcemia ), and may affect different parts of the body. They include:
Exams and Tests:
Parathyroid cancer is very hard to diagnose.
Your doctor will perform a physical exam and ask about your medical history.
About half of the time, feeling the neck with the hands (palpation ) can reveal a cancerous parathyroid tumor.
A cancerous parathyroid tumor tends to produce a very high amount of parathyroid hormone (PTH). Tests for this hormone may include:
Before surgery, you will have a special radioactive scan of the parathyroid glands. The scan is called the sestamibi scan. You may also have a neck ultrasound . These tests are done to confirm which parathyroid gland is abnormal.
The following treatments may be used to correct hypercalcemia due to parathyroid cancer:
- A drug called gallium nitrate, which lowers the calcium level in the blood
- A natural hormone called calcitonin that helps control calcium level
- Drugs that stop the breakdown and reabsorption of bones into the body
- Fluids through a vein (IV fluids)
Surgery is the recommended treatment for parathyroid cancer. Sometimes it is hard to determine whether a parathyroid tumor is cancerous. Your doctor may recommend surgery even without a confirmed diagnosis. Minimally invasive surgery, using smaller cuts, is becoming more common for parathyroid disease.
If tests before the surgery can find the affected gland, surgery may be done on one side of the neck. If it is not possible to find the problem gland before surgery, the surgeon will look at both sides of your neck.
Chemotherapy and radiation do not work well in preventing the cancer from coming back. Radiation can sometimes help reduce the spread of cancer to the bones. Repeated surgeries for cancer that has returned may increase survival rate and reduce the severe effects of hypercalcemia.
Parathyroid cancer is slow growing. Surgery may help extend life even when the cancer spreads.
The cancer may spread (metastasize) to other places in the body, most commonly the lungs and bones.
The most serious complication of parathyroid cancer is hypercalcemia. Most deaths from parathyroid cancer occur as a result of severe, difficult to control hypercalcemia, and not the cancer itself.
The cancer commonly comes back (recurs). Additional surgeries may be needed. Complications from surgery can include:
- Hoarseness or voice changes as a result of damage to the nerve that controls the vocal cords
- Infection at the site of surgery
- Low level of calcium in the blood (hypocalcemia), a potentially life-threatening condition
When to Contact a Medical Professional:
Call your health care provider if you feel a lump in your neck or experience symptoms of hypercalcemia.
Mohebati A, Shaha A, Shah J. Parathyroid carcinoma. Hematol Oncol Clin N Am. 2012;26:1221–1238.
National Cancer Institute: PDQ Parathyroid Cancer Treatment. Bethesda, Md: National Cancer Institute. Date last modified: November 8, 2013. Available at: http://cancer.gov/cancertopics/pdq/treatment/parathyroid/HealthProfessional. Accessed: March 23, 2014.
Schneider DF, Mazeh H, Lubner SJ, et al. Cancer of the endocrine system. In: Niederhuber JE, Armitage JO, Doroshow JH, et al., eds. Abeloff's Clinical Oncology. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2013:chap 71.