What are the parathyroid glands?
The parathyroid glands are two pair (four in total) of glands that secrete parathyroid hormone. The parathyroid gland, like the THYROID GLAND, is part of the endocrine (gland) system.
What is parathyroid hormone?
Parathyroid hormone is a substance that helps regulate the amount of calcium in the bloodstream. Calcium is needed to make strong bones and teeth. However, a normal calcium level in the bloodstream is also very important for normal function of muscles and nerves. Parathyroid hormone raises the amount of calcium in the bloodstream by removing calcium from bones, by increasing the amount of calcium taken from the diet, and by decreasing the amount of calcium excreted in the urine.
Where are the parathyroid glands located?
The parathyroid glands are located behind the two lobes of the THYROID GLAND in the neck.
What problems can develop with the parathyroid gland?
One or more of the parathyroid glands can become overactive, secreting too much parathyroid hormone (hyperparathyroidism) or under active, secreting too little parathyroid hormone (hypoparathyroidism). The parathyroid hormone secreted may not be effective in the body for various reasons, which is considered a form of hypoparathyroidism. It is important to note that problems with the parathyroid glands, especially overactive glands, usually develop in adulthood, and are rare in children.
How are parathyroid diseases treated?
An endocrinologist (hormone specialist) usually manages a patient with hypoparathyroidism (which causes too low calcium levels in the bloodstream). Bloodstream calcium levels are important in muscle and nerve function. A low calcium level can cause painful muscle spasms (tetany). Unlike thyroid hormone, there is currently no replacement medication for parathyroid hormone, so treatment usually consists of calcium and Vitamin D (important for the absorption of calcium) supplements.
Hyperparathyroidism is most commonly caused by a benign (not cancer) tumor called an adenoma. However, less commonly, it can result from regulation problems with all the glands (hyperplasia) or parathyroid gland cancer (which is very rare).
The symptoms associated with hyperparathyroidism include generalized bone aches and pains, abdominal pain, and depression (please see “what if the overactive parathyroid glands are not removed” below). An endocrinologist or another physician experienced in parathyroid problems usually makes this diagnosis. Once this diagnosis is made, parathyroid surgery (PARATHYROIDECTOMY) is usually curative.
A more recently developed procedure called Minimally Invasive Radioguided Parathyroidectomy (MIRP) has been advocated for treatment of single parathyroid adenomas in adults. This procedure involves making the overactive parathyroid gland radioactive. An instrument can then locate the radioactive gland in the neck, and a precise incision to remove that specific parathyroid gland can be performed. It results in a much smaller incision than traditional parathyroidectomy and a more rapid recovery time. However, MIRP has not been used extensively in children and is mentioned here only for completeness.
Finally, some physicians have tried a medication that increases calcium in bone as treatment, trying to avoid surgery; however, medication alone is not generally recommended for adults, and is especially not a consideration in children.
When would an ear, nose, and throat specialist be consulted?
Because of the location of the parathyroid glands in the neck, the otolaryngologist (ear, nose, and throat specialist) is usually consulted to perform a parathyroidectomy. As mentioned above, this type of surgery is uncommon in childhood; therefore, an ear, nose, and throat specialist with significant pediatric experience is probably the best qualified to perform this procedure.
What would happen if the overactive parathyroid glands were not removed?
The parathyroid hormone acts to increase the amount of calcium in the bloodstream. As it gets this calcium from bones in the body, bones will eventually become brittle and easily broken. Parathyroid hormone also prevents calcium from being excreted by the kidneys; this extra calcium can create kidney stones. High calcium levels can also affect the lining of the stomach and the pancreas (an organ located near the stomach), causing irritation, ulcers, and inflammation. Finally, high calcium levels can cause a person to feel irritable or have difficulty falling asleep.
The longer the overactive glands remain in place, the more severe the above complications will become.
Although extremely rare, the parathyroid gland may become cancerous, and not removing it may result in spread of the cancer to other areas of the body.
How many parathyroid glands will need to be removed?
There are four parathyroid glands, however, commonly only one gland is affected (single adenoma). Removal of this overactive gland should result in normal parathyroid function. In other cases, more than one gland is involved and will need to be removed. There are specific parathyroid studies (Sestambi scanning or SPECT scanning) that are available to determine the location of the glands that are abnormal. In addition, sometimes, medicine is injected into the body, which will dye the parathyroid glands a certain color so that they are easier to located and remove during surgery.