The thyroid is a gland in the front of the neck. It makes hormones that help control how the body works. This includes how the body uses energy (metabolism).
Thyroid cancer happens when cancer cells grow in the thyroid. There are four main types of thyroid cancer:
Papillary cancer. This is the least harmful type. It mainly affects females of childbearing age.
Follicular cancer. This type is the most likely to come back after treatment (recur). It is also the most likely to spread to other parts of the body (metastasize).
Medullary cancer. This type can be passed from parent to child (inherited). If you inherit the gene for this cancer, you are at high risk for getting this cancer.
Anaplastic cancer. This type may spread quickly to the windpipe (trachea). It can cause breathing problems. It is most common among people who are 65 years of age or older.
What are the causes?
The exact cause of thyroid cancer is not known.
What increases the risk?
You may be more likely to get thyroid cancer if:
You have ever been exposed to radiation of the head, neck, or chest. You may be more at risk if you were exposed to it as a baby or a child.
You have a thyroid that is larger than normal (enlarged). This may also be called a goiter.
You have a family history of thyroid disease.
You are female.
What are the signs or symptoms?
Symptoms may include:
How is this diagnosed?
Thyroid cancer may be diagnosed based on your symptoms and medical history.
You may also have tests, such as:
Imaging tests of your neck. These may include an ultrasound, CT scan, MRI, or PET scan.
Biopsy. This is when a tissue sample is removed and looked at under a microscope. This may be done to find out what type of thyroid cancer you have.
Your cancer will be assessed (staged) based on how severe it is and how much it has spread.
How is this treated?
Most thyroid cancers are treated with surgery to remove most or all of the thyroid (thyroidectomy). In some cases, the lymph nodes in the neck that are close to the thyroid may also be taken out. Lymph nodes are part of the body's defense system (immune system). They are often the first place that cancer spreads to.
Treatment may also include:
- Radioactive iodine treatment. This is a procedure in which you swallow a substance (radioactive iodine, or radioiodine). The iodine is absorbed by your thyroid. Then it destroys cancer cells. You may need this to:
Chemotherapy. These are medicines that kill cancer cells.
Radiation therapy. This is when high-energy rays are used to kill cancer cells. You may have this if your cancer has spread to your bones.
Alcohol ablation. This is a procedure to kill cancer cells. It is done by injecting them with alcohol.
Immunotherapy. These are medicines that help your body's immune system fight the cancer cells.
- Thyroid hormone therapy. This can:
Replace the hormone in the body that is normally made by the thyroid.
Stop or slow down (suppress) the work of thyroid-stimulating hormone (TSH). In normal cases, TSH tells the thyroid how much thyroid hormone to make.
Follow these instructions at home:
Take over-the-counter and prescription medicines only as told by your health care provider.
Think about joining a support group for people who have thyroid cancer.
Eat a healthy diet that includes fruits and vegetables, whole grains, lean protein, and low-fat or nonfat dairy products.
Work with your provider to manage any side effects of treatment.
Keep all follow-up visits. Your provider will need to monitor your cancer and treatment.
Where to find more information
Contact a health care provider if:
These symptoms may be an emergency. Get help right away. Call 911.
This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.