Parathyroid Tumors: Patient Education

Cancer Facts
  • Cancer of the parathyroid gland is rare; most tumors originating at the parathyroid gland are noncancerous (benign).
  • According to the American Society of Clinical Oncologists, there are fewer than 100 cases of parathyroid cancer in the United States each year.
  • Parathyroid cancer affects men and women equally.


A parathyroid tumor is a growth of cells inside one of your four parathyroid glands. These growths are almost always noncancerous (benign). Benign masses are called adenomas.

Parathyroid tumors are rarely cancerous (malignant), but may be suspected in patients with very high calcium levels or in patients who have a family history or develop severe hyperparathyroidism at a young age.

Your Parathyroid Glands

Your parathyroid glands are four small glands in your neck behind your thyroid gland. They’re each about the size of a small watermelon seed. Generally, there are two parathyroid glands, an upper and a lower, on each side of your neck.

Your parathyroid glands are part of your endocrine system. Your endocrine system is a system of glands and cells that make hormones that are released directly into your blood and travel to tissues and organs all over your body. Your endocrine system controls:

  • Growth
  • Sexual development
  • Hunger
  • Sleep
  • Metabolism

Your parathyroid glands make parathyroid hormone (PTH, or parathormone), a hormone that controls the levels of calcium and phosophorus in your blood. The primary purpose of your parathyroid glands is to regulate your body’s calcium levels within a tight range so that your muscular and nervous systems function correctly.


Tumors on your parathyroid gland can cause your parathyroid gland to make too much PTH, causing hyperparathyroidism.

It’s important to understand that 99.5 percent of hyperparathyroidism is caused by benign adenomas. Parathyroid cancer is very rare.

— Terry C. Lairmore, MD, Endocrine Surgeon and Chief of Surgical Oncology

With hyperparathyroidism, the extra PTH causes two dangerous results:

  • Calcium stored in your bones moves into your blood
  • Your intestines absorb more calcium from the food you eat

Elevated levels of calcium in your blood is called hypercalcemia. Sometimes the hypercalcemia can be as dangerous as parathyroid cancer itself.

Severe hypercalcemia can result in:

  • Dementia
  • Depression
  • Confusion
  • Muscular weakness
  • Bowing of the shoulders
  • Bone fractures
  • Loss of height
  • Spinal column curvature
  • Kidney stones
  • Kidney failure
  • High blood pressure
  • Pancreatitis
  • Peptic ulcer disease
  • Coma
  • Cardiac arrest

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Related Resources

Additional information about parathyroid cancer:

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