Thyroid cancer is a disease that you get when abnormal cells begin to grow in your thyroid gland. The thyroid gland is shaped like a butterfly and is located in the front of your neck. It makes hormones that regulate the way your body uses energy and that help your body work normally.
Although thyroid cancer isn't common in the United States, rates seem to be increasing. Some suggest this is because new technology is allowing them to find small thyroid cancers that may not have been found in the past.
Most cases of thyroid cancer can be cured with treatment. Experts don't know the causes of thyroid cancer but past radiation treatment of your head, neck, or chest (especially during childhood) is linked to an increased risk of getting thyroid cancer.
If you have any signs or symptoms that suggest you might have thyroid cancer, your health care professional will want to know your complete medical history. You will be asked questions about your possible risk factors, symptoms, and any other health problems or concerns. If someone in your family has had thyroid cancer (especially medullary thyroid cancer) or tumors called pheochromocytomas, it is important to tell your doctor, as you might be at high risk for this disease.
Your doctor will examine you to get more information about possible signs of thyroid cancer and other health problems. During the exam, the doctor will pay special attention to the size and firmness of your thyroid and any enlarged lymph nodes in your neck.
The actual diagnosis of thyroid cancer is made with a biopsy, in which cells from the suspicious area are removed and looked at under a microscope. However, your doctor will order other tests first to get a better sense of whether you might have thyroid cancer.
Blood tests are not used to find thyroid cancer. But they can help show if your thyroid is working normally, which may help the doctor decide what other tests may be needed. For example tests of blood levels of thyroid-stimulating hormone (TSH) may be used to check the overall activity of your thyroid gland. This information can be used to help choose which imaging tests (such as ultrasound or radioiodine scans) to use to look at a thyroid nodule. T3 and T4 are the main hormones made by the thyroid gland. Levels of these hormones may also be measured to get a sense of thyroid gland function. TSH, T3 and T4 levels are usually normal in thyroid cancer.
Imaging tests may be done for a number of reasons, including helping find suspicious areas that might be cancer, to learn how far cancer may have spread, and to help determine if treatment is working.
Ultrasound can help determine if a thyroid nodule is solid or filled with fluid. (Solid nodules are more likely to be cancerous.) It can also be used to check the number and size of thyroid nodules. How a nodule looks on ultrasound can sometimes suggest if it is likely to be a cancer, but ultrasound can't tell for sure. Ultrasound can also be used to guide a biopsy needle into the nodule to obtain a sample.
Radioiodine scans can be used to help determine if someone with a lump in the neck might have thyroid cancer. They are also often used to help show if a cancer it has spread. A small amount of radioactive iodine (called I-131) is swallowed (usually as a pill) or injected into a vein. Over time, the iodine is absorbed by the thyroid gland (or thyroid cells anywhere in the body). A special camera is used several hours later to see where the radioactivity is. Abnormal areas of the thyroid that have less radioactivity than the surrounding tissue are called cold nodules, and areas that take up more radiation are called hot nodules. Hot nodules usually are not cancerous, but cold nodules can be benign or cancerous. Because both benign and cancerous nodules can appear cold, this test by itself can't diagnose thyroid cancer.
Computed tomography (CT) scan
The CT scan is an x-ray test that produces detailed cross-sectional images of your body. It can help determine the location and size of thyroid cancers and whether they have spread to nearby areas, although ultrasound is usually the test of choice. A CT scan can also be used to look for spread into distant organs such as the lungs.
Magnetic resonance imaging (MRI) scan
Like CT scans, MRI scans can be used to look for cancer in the thyroid, or cancer that has spread to nearby or distant parts of the body. But ultrasound is usually the first choice for looking at the thyroid. MRI can provide very detailed images of soft tissues such as the thyroid gland. MRI scans are also very helpful in looking at the brain and spinal cord.
If your doctor thinks a biopsy is needed, the simplest way to find out if a thyroid lump or nodule is cancerous is with a fine needle aspiration (FNA) of the thyroid nodule. Small samples of tissue and fluid are taken from several areas of the nodule using a thin hollow needle. The biopsy samples are then sent to a lab for examination. Doctors often use ultrasound to see the thyroid during the biopsy, which helps make sure they are getting samples from the right areas.
Depending on the type and stage of your thyroid cancer, you may need more than one type of treatment. Doctors on your cancer treatment team may include:
Many other specialists may be involved in your care as well, including nurse practitioners, nurses, psychologists, social workers, rehabilitation specialists, and other health professionals.
After thyroid cancer is found and staged, your cancer care team will discuss your treatment options with you. It is important to take the time to consider each of your options. In choosing a treatment plan, factors to consider include the type and stage of the cancer and your general health. The treatment options for thyroid cancer might include:
Often 2 or more of these options are combined.
Most thyroid cancers can be cured, especially if they have not spread to distant parts of the body. If the cancer can't be cured, the goal of treatment may be to remove or destroy as much of the cancer as possible and to keep it from growing, spreading, or returning for as long as possible. Sometimes treatment is aimed at palliating (relieving) symptoms such as pain or problems with breathing and swallowing.
Surgery is the most common treatment of cancer of the thyroid. A doctor may remove the cancer using one of the following operations: