The thyroid is a butterfly-shaped gland located in the neck, below the Adam's apple.
Hormones made by the thyroid are also important during childhood growth and development.
The thyroid uses iodine, a mineral found in iodized salt and in some foods, to make several of its hormones. Thyroid cancer is a disease in which thyroid cells become abnormal, grow out of control, and form a cancerous tumor . If left untreated, thyroid cancer can spread to other parts of the body through a process called metastasis . In 1997 an estimated 16,100 people in the United States will be diagnosed with thyroid cancer. This disease, which is the most common cancer of the endocrine system, accounts for about 1 percent of all cancers.