Located just below your Adam’s apple in the front of your neck, the thyroid gland is a little bigger than a quarter. This small butterfly-shaped gland uses iodine from the foods we eat to make essential hormones that regulate metabolism (the physical and chemical changes that take place in the body, providing energy for cell growth and functioning).
The thyroid gland has two main cell types: thyroid follicular cells and C cells (calcitonin-producing cells). The follicular cells take iodine from the food you eat and make thyroid hormones, T3 and T4, which regulate your metabolism. The C cells make the hormone calcitonin, but the role of calcitonin in your health is unknown. The thyroid also has immune system cells called lymphocytes and supportive, or stromal, cells.
The thyroid commonly develops cysts or nodules. While most nodules (90 percent) are benign, each year in the United States more than 28,000 women and 8,500 men are diagnosed with thyroid cancer. Cancerous tumors can occur in either of the two cell types: follicular or C cells. The type of cancer depends on which cells are involved.
Early in the disease process, thyroid cancer may not present any symptoms. But as the tumor grows, it may create pressure causing symptoms such as the following:
- a lump you can feel in the front of your neck
- difficulty breathing
- difficulty swallowing
- a cough that doesn’t go away
- throat or neck pain that lasts more than two weeks
If you experience any of these symptoms, you should discuss them with your doctor. They may be signs of thyroid cancer or of another condition.