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.

Having certain inherited disorders can increase the risk of developing 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.

Possible signs of parathyroid cancer include weakness, feeling tired, and a lump in the neck.

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.

Other symptoms of parathyroid cancer include the following:

—      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.

Other conditions may cause the same symptoms as parathyroid cancer. A doctor should be consulted if any of these problems occur.

Tests that examine the neck and blood are used to detect (find) and diagnose parathyroid cancer.

Once blood tests are done and hyperparathyroidism is diagnosed, imaging tests may be done to help find which of the parathyroid glands is overactive. Sometimes the parathyroid glands are hard to find and imaging tests are done to find exactly where they are.

Parathyroid cancer may be hard to diagnose because the cells of a benign parathyroid adenoma and a malignant parathyroid cancer look alike. The patient’s symptoms, blood levels of calcium and parathyroid hormone, and characteristics of the tumor are also used to make a diagnosis.

The following tests and procedures may be used:

—      Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.

—      Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it. To diagnose parathyroid cancer, the sample of blood is checked for its calcium level.

—      Parathyroid hormone test: A procedure in which a blood sample is checked to measure the amount of parathyroid hormone released into the blood by the parathyroid glands. A higher than normal amount of parathyroid hormone can be a sign of disease.

—      Sestamibi scan: A type of radionuclide scan used to find an overactive parathyroid gland. A small amount of a radioactive substance called technetium 99 is injected into a vein and travels through the bloodstream to the parathyroid gland. The radioactive substance will collect in the overactive gland and show up brightly on a special camera that detects radioactivity.

—      CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.

—      Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.

—      Angiogram: A procedure to look at blood vessels and the flow of blood. A contrast dye is injected into the blood vessel. As the contrast dye moves through the blood vessel, x-rays are taken to see if there are any blockages.

—      Venous sampling: A procedure in which a sample of blood is taken from specific veins and checked to measure the amounts of certain substances released into the blood by nearby organs and tissues. If imaging tests do not show which parathyroid gland is overactive, blood samples may be taken from veins near each parathyroid gland to find which one is making too much PTH.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on the following:

—      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.

Stages of Parathyroid Cancer

Staging is the process used to find out how far the cancer has spread. The following imaging tests may be used to determine if cancer has spread to other parts of the body such as the lungs, liver, bone, heart, pancreas, or lymph nodes:

CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.

MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).

There is no standard staging process for parathyroid cancer. The disease is described as either localized or metastatic.

—      Localized parathyroid cancer is found in a parathyroid gland and may have spread to nearby tissues.

—      Metastatic parathyroid cancer has spread to other parts of the body, such as the lungs, liver, bone, sac around the heart, pancreas, or lymph nodes.

Recurrent Parathyroid Cancer

 Recurrent parathyroid cancer is cancer that has recurred (come back) after it has been treated. More than half of patients have a recurrence. The parathyroid cancer usually recurs between 2 and 5 years after the first surgery, but can recur up to 20 years later. It usually comes back in the tissues or lymph nodes of the neck. High blood calcium levels that appear after treatment may be the first sign of recurrence.

Treatment Option Overview

—      There are different types of treatment for patients with parathyroid cancer.

—      Treatment includes control of hypercalcemia (too much calcium in the blood) in patients who have an overactive parathyroid gland.

—      Four types of standard treatment are used:

—      Surgery

—      Radiation therapy

—      Chemotherapy

—      Supportive care

—      New types of treatment are being tested in clinical trials.

—      Lifelong follow-up is important.

There are different types of treatment for patients with parathyroid cancer.

Different types of treatment are available for patients with parathyroid cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

Clinical trials are taking place in many parts of the country.  Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.

Treatment includes control of hypercalcemia (too much calcium in the blood) in patients who have an overactive parathyroid gland.

In order to reduce the amount of parathyroid hormone that is being made and control the level of calcium in the blood, as much of the tumor as possible is removed in surgery. For patients who cannot have surgery, medication may be used.

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