Thyroid cancer

Thyroid cancer is a disease in which malignant (cancer) cells form in the tissues of the thyroid gland. The thyroid is a butterfly-shaped gland at the base of the throat near the trachea (windpipe) that makes hormones which help control heart rate, body temperature, and metabolism, and that help regulate blood calcium levels. There are four main types of thyroid cancer — papillary, follicular, medullary, and anaplastic — which differ in how aggressive they are, with papillary being the most common. Thyroid cancer that is found at an early stage can often be treated successfully.

Assigned stages I–IV, with the staging system varying by tumor type and patient age (e.g., papillary/follicular cancers in patients under 55 use a simpler two-stage system; anaplastic cancer is always stage IV).