Ask the Doctors

Dear Doctor: When does a person require parathyroid surgery? I've heard it discussed, but don't know much about it.

Dear Reader: As their name implies, the parathyroid glands are located next to the thyroid gland. You have four of them, two on each side, behind the thyroid gland in the neck. The parathyroid glands help regulate calcium and potassium levels in the bloodstream. They do this through the production of parathyroid hormone, which is produced in varying quantities depending upon the levels of calcium, phosphorus and vitamin D. As the calcium levels increase, the levels of parathyroid hormone decrease and vice versa.

Sometimes, however, the parathyroid glands overproduce parathyroid hormone, causing levels of calcium to increase. Primary hyperparathyroidism is the overproduction of parathyroid hormone due to a defect with the gland. This occurs in three in 1,000 people, and is more prevalent between the ages of 50 and 65; women are three times more likely than men to have the condition.

In 80 to 85 percent of cases, primary hyperparathyroidism is due to a benign tumor on one of the parathyroid glands. About 6 percent of the time, primary hyperparathyroidism is related to enlargement of two or more parathyroid glands. Only rarely, in 1 to 2 percent of cases, parathyroid cancer is the cause of this hormone elevation.

Most hyperparathyroidism symptoms aren't obvious. The condition is generally found incidentally after a blood test shows a high calcium level. In such cases, patients have often complained of fatigue, weakness, decreased appetite and difficulties with mental tasks. The classical symptoms of primary hyperparathyroidism are a depressed mood, nausea, poor appetite, increased thirst, increased urination, kidney stones and, very rarely, bone pain and psychosis. Of note, people with this condition have a two- to threefold increased risk of bone fractures. Further, when primary hyperparathyroidism is severe, the high calcium levels can lead to confusion and even coma.

In such severe cases, surgery is obviously warranted. It is also indicated if calcium blood levels are greater than 1 mg/dl above the upper limit of normal; if a person has osteoporosis, kidney stones or kidney dysfunction; or if the person is younger than 50.

But, if calcium levels are only mildly elevated, it isn't clear that surgery is necessary. That said, people who have had surgery due to mild calcium elevations have noted increases in bone density, decreased incidence of kidney stones and slight improvement of mood.

For a less invasive surgery, it is important to determine which of the glands is overproducing parathyroid hormone. This is normally done with a SPECT scan and an ultrasound. In the hands of an experienced surgeon, this assessment will lead to a smaller incision, less operating time and less damage to surrounding tissues.

However, when high levels are caused by multiple glands overproducing parathyroid hormone (which occurs 15 percent of the time) or if a thyroid abnormality is also found, then a more extensive surgical exploration is needed. A significant drop in blood calcium levels can happen after surgery, so the levels need to be monitored afterward.

Not everyone is a candidate for surgery. If this is the case, medications like Cinacalcet can lower calcium levels, and bisphosphonates, like Fosamax, can improve bone density.

As with every condition, each person's needs are different.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

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