Thyroid cancer occurs when cancerous cells form in the tissues of the thyroid, a butterfly-shaped gland located at the front of the neck. There are usually no early signs or symptoms. However, as the cancer grows, symptoms may include difficulty swallowing, swollen lymph nodes, and pain in the throat or neck. Treatment options for thyroid cancer include surgery, hormone therapy, chemotherapy, and radioactive iodine treatment.
Thyroid cancer is a disease in which cancer cells first develop in the tissues of the thyroid.
The thyroid is a gland that is shaped like a butterfly and lies at the front of the neck, beneath the voice box (larynx).
A healthy thyroid:
- Is a little larger than a quarter and cannot be felt through the skin
- Is made up of two parts (lobes) that are separated by a thin section called the isthmus
- Has two kinds of cells, follicular cells and C cells, which produce hormones.
Follicular cells make thyroid hormone, which affects heart rate, body temperature, and a person's energy levels. C cells make calcitonin, which is a hormone that helps control the level of calcium in the blood. A swollen lobe (goiter) might look or feel like a lump in the front of the neck and is usually the result of not getting enough iodine in the diet. Iodine is a substance that is found in shellfish and iodized salt.
There are four main types of thyroid cancer that may be distinguished from each other based on how the cancer cells look under a microscope. These types include:
If the cancer spreads outside of the thyroid, it is called metastatic thyroid cancer.
(Click Types of Thyroid Cancer for more information.)