Parathyroid cancer is rarer than thyroid cancer and more difficult to treat. In the United States fewer than 100 people are diagnosed with parathyroid cancer each year.
Almost everybody has four parathyroid glands—each about the size of a grain of rice—although some people have more than twice that many. The parathyroid glands may be tiny, but they have a big influence on your health: they regulate your body’s calcium levels, which can affect your heart, kidneys, bones, and nervous system.
In most people, the parathyroid glands are located just in back of the thyroid gland, at the front of the throat. But sometimes they’re found in other places, including the chest or even inside the thyroid gland.
Note that the thyroid and parathyroid glands are completely different organs. The name parathyroid just describes the fact that these tiny glands are close to the thyroid gland.
Radiation exposure (including radiation treatments to the head and neck) and long-term use of the drug lithium are risk factors for parathyroid cancer. In some cases, parathyroid cancer is caused by an inherited gene mutation called HRPT2.
Symptoms of parathyroid cancer include:
Parathyroid cancer is usually treated by removing the affected parathyroid glands, a procedure called parathyroidectomy. In most cases, surgeons will also remove part of the thyroid gland (the “lobe” on the same side as the parathyroid gland that is being removed, plus the “isthmus” between the two thyroid lobes) as well as lymph nodes around the targeted parathyroid gland and any tissue connected to the tumor.