Tumours of the parathyroid glands
Parathyroid tumours can be non-cancerous (benign) or cancerous (malignant). Most tumours of the parathyroid gland are benign. Cancer of the parathyroid gland is extremely rare. This information is about cancer of the parathyroid glands.
The parathyroid glands are part of the endocrine system, so these tumours are also known as endocrine tumours.
We hope this information answers your questions. If you have any further questions, you can ask your doctor or nurse at the hospital where you are having your treatment.
The endocrine system is a network of endocrine glands and nerves throughout the body. Endocrine glands produce and release hormones that circulate around the body in the blood. Hormones keep an even balance of chemicals and fluid within the body, and help us respond to changes in the environment.
The endocrine glands include the pituitary gland (which lies directly underneath the brain), the thyroid gland (in the front of the neck), the parathyroid glands (just behind the thyroid gland), and the adrenal glands (one on top of each kidney in the abdomen).
Although the thyroid gland and the parathyroid glands are close to each other and have similar names, they have very different functions.
The parathyroid glands
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There are four parathyroid glands, which are attached to the thyroid gland in the front of the neck.
The parathyroid glands are small, but their function is very important. They maintain the correct levels of calcium in the body. Calcium plays an essential role in controlling muscle and nerve function.
Tumours of the parathyroid gland
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A tumour of the parathyroid gland may cause overproduction of the hormone that controls the level of calcium in the body. This hormone is called parathyroid hormone (PTH) or parathormone.
Causes and risk factors of parathyroid tumours
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The exact cause of parathyroid tumours is not fully understood. People affected by a condition known as multiple endocrine neoplasia 1 (MEN1) have an increased risk of developing parathyroid tumours. This is a rare condition that is caused by a faulty gene. It can be passed on from one generation to another (inherited).
Cancer of the parathyroid glands has also been linked to exposure to radiation.
Signs and symptoms of parathyroid tumours
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Some people with a parathyroid tumour may feel a lump or swelling in their neck, but this is not common.
If parathyroid hormone is being overproduced, it may cause some of the following signs and symptoms:
Many people with tumours of the parathyroid glands will have no symptoms and some people may only have one or two. These symptoms may also be caused by conditions other than cancer, but it's important to get them checked.
How parathyroid tumours are diagnosed
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Your doctor will begin by asking you about your medical history and any symptoms that you have.
A number of tests will be done. These may include any of the following.
Blood and urine tests
Samples of blood and urine are checked for the presence of certain hormones. A sample of urine may be collected over a 24-hour period. Sometimes it's necessary to fast (not eat) overnight before having certain blood tests.
This scan can show the size and position of the parathyroid glands, and how well they are working. A slightly radioactive substance is injected into a vein in your arm. The scan shows how much of the substance is taken up by the parathyroid glands, and identifies any abnormal areas.
X-rays and scans
A combination of x-rays and scans will be taken to find where the tumour is, and whether it has spread.
This scan uses sound waves to build up a picture of the neck area. Once you’re lying comfortably on your back, a gel is spread over your neck. A small device like a microphone, which produces sound waves, is then moved over the area. The sound waves are converted into a picture using a computer.
CT (computerised tomography) scan
A CT scan takes a series of x-rays that build up a three-dimensional picture of the inside of the body. The scan is painless and takes 10-30 minutes. CT scans use a small amount of radiation, which will be very unlikely to harm you and will not harm anyone you come into contact with. You will be asked not to eat or drink for at least four hours before the scan.
You may be given a drink or injection of a dye, which allows particular areas to be seen more clearly. For a few minutes, this may make you feel hot all over. If you are allergic to iodine or have asthma you could have a more serious reaction to the injection, so it’s important to let your doctor know this beforehand.
MRI (magnetic resonance imaging) scan
This test is similar to a CT scan but uses magnetism instead of x-rays to build up a detailed picture of areas of your body. Before the scan you may be asked to complete and sign a checklist. This is to make sure that it’s safe for you to have an MRI scan.
Before having the scan, you’ll be asked to remove any metal belongings including jewellery. Some people are given an injection of dye into a vein in the arm. This is called a contrast medium and can help the images from the scan to show up more clearly.
During the test you’ll be asked to lie very still on a couch inside a long cylinder (tube) for about 30 minutes. It’s painless but can be slightly uncomfortable, and some people feel a bit claustrophobic during the scan. It’s also noisy, but you’ll be given earplugs or headphones. You'll be able to hear, and speak to, the person operating the scanner.
PET (positron emission tomography) scan
This is a new type of scan that is occasionally used for this type of tumour. A PET scan uses low-dose radioactive sugar to measure the activity of cells in different parts of the body. Areas of tumour are usually more active than surrounding tissue, and show up on the scan. If you need a PET scan, you might have to travel to a specialist centre to have one.
A small sample of cells is taken from the tumour to be examined under a microscope. The biopsy may be carried out under a local or general anaesthetic.
Treatment for parathyroid tumours
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If the tumour is contained in one area (localised) or if there has been only limited spread, surgery is usually the first choice of treatment. If it is possible to remove the tumour completely, you might not need any other treatment.
Surgery involves removing all of the parathyroid gland and part or all of the nearest half of the thyroid gland, as well as some surrounding tissue. After the operation, the calcium levels in the body can go up and down. Your doctors will monitor your calcium level by taking regular blood tests.
Usually, this type of surgery is done under a general anaesthetic and requires a short stay in hospital.
This is the use of high-energy rays to destroy cancer cells. Radiotherapy can be given after surgery to reduce the risk of the cancer coming back. It may also be given if your cancer comes back some time after the surgery, or if it has spread to another part of the body.
This is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. Chemotherapy is occasionally used for parathyroid cancer that has come back after initial treatment, or has spread to other parts of the body.
Medicines known as bisphosphonates can be given to reduce high levels of calcium in the blood (hypercalcaemia).
These medicines are used to reduce overproduction of parathyroid hormone (PTH).
Research into treatments for parathyroid tumours is ongoing and advances are being made. Cancer specialists use clinical trials to assess new treatments. Before any trial is allowed to take place, an ethics committee must approve it and agree that the trial is in the interest of the patients.
You may be asked to take part in a clinical trial. Your doctor will discuss the treatment with you so that you have a full understanding of the trial and what it involves. You may decide not to take part or to withdraw from a trial at any stage. You will still receive the best standard treatment available.
You may have many different emotions including anger, resentment, guilt, anxiety and fear. These are all normal reactions, and are part of the process many people go through in trying to come to terms with their condition.
Everyone has their own way of coping with difficult situations. Some people find it helpful to talk to family or friends, while others prefer to seek help from people outside their situation. Some people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is there if you need it. Our cancer support specialists can give you information about counselling in your area.
This information has been compiled using a number of reliable sources, including:
Clark, et al. Endocrine Tumours. 2003. BC Decker Inc.
NNCN. www.nccn.com (accessed September 2012).
Raghavan, et al. The Textbook of Uncommon Cancers. 3rd edition. 2006. Wiley.
Souhami, et al. Oxford Textbook of Oncology. 2nd edition. 2001. Oxford University Press.
UpToDate. www.uptodate.com (accessed September 2012).
Thanks to Professor John Monson, Professor of Endocrinology, and the people affected by cancer who reviewed this edition. Reviewing information is just one of the ways you could help when you join our Cancer Voices network.