Parathyroid Tumor

What are parathyroid tumors?

Parathyroid cancer is a rare disease in which malignant (cancer) cells form in the tissues of a parathyroid gland. The parathyroid glands are four pea-sized organs found in the neck near the thyroid gland. The parathyroid glands make parathyroid hormone (PTH or parathormone). PTH helps the body use and store calcium to keep the calcium in the blood at normal levels. A parathyroid gland may become overactive and make too much PTH, a condition called hyperparathyroidism. Hyperparathyroidism can occur when a benign tumor (noncancer), called an adenoma, forms on one of the parathyroid glands, and causes it to grow and become overactive. Sometimes hyperparathyroidism can be caused by parathyroid cancer, but this is very rare. The extra PTH causes:

• The calcium stored in the bones to move into the blood
• The intestines to absorb more calcium from the food we eat
• This condition is called hypercalcemia (too much calcium in the blood).

The hypercalcemia caused by hyperparathyroidism is more serious and life-threatening than parathyroid cancer itself and treating hypercalcemia is as important as treating the cancer.

What are the risk factors for parathyroid cancer?

Anything that increases the chance of getting a disease is called a risk factor. Risk factors for parathyroid cancer include the following rare disorders that are inherited (passed down from parent to child): 

• Familial isolated hyperparathyroidism (FIHP)
• Multiple endocrine neoplasia type 1 (MEN1) syndrome

Treatment with radiation therapy may increase the risk of developing a parathyroid adenoma.

What are the symptoms of parathyroid cancer?

Possible signs of parathyroid cancer include weakness, feeling tired, and a lump in the neck. Other conditions may cause the same symptoms as parathyroid cancer. A doctor should be consulted if any of these problems occur. 

• Pain in the abdomen, side, or back that doesn't go away
• Pain in the bones
• A broken bone
• A lump in the neck
• Change in voice such as hoarseness
• Trouble swallowing

Most parathyroid cancer symptoms are caused by the hypercalcemia that develops. Symptoms of hypercalcemia include the following: 

• Weakness
• Feeling very tired
• Nausea and vomiting
• Loss of appetite
• Weight loss for no known reason
• Being much more thirsty than usual
• Urinating much more than usual
• Constipation
• Trouble thinking clearly

What is the prognosis (chance of recovery) for patients diagnosed with a parathyroid tumor?

Recovery may depend on: 

• Whether the calcium level in the blood can be controlled
• The stage of the cancer
• Whether the tumor and the capsule around the tumor can be completely removed by surgery
• The patient's general health

About PDQ and This Cancer Information Summary

PDQ is the National Cancer Institute's (NCI's) comprehensive cancer information database. PDQ is provided as a service of the NCI. The NCI is part of the National Institutes of Health, the federal government's focal point for biomedical research. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. The PDQ cancer information summaries are developed by cancer experts and reviewed regularly.