The thyroid is a small gland located below the voice box in the front of the neck. It is made up of two lobes and is shaped like a butterfly. As part of your endocrine system, this gland makes hormones that affect your heart rate, temperature, mental function, and metabolism.

If cells in the thyroid gland grow uncontrollably, they form a nodule (tumor). Most (90 percent) of thyroid nodules are benign (noncancerous). But 1 out of 10 are malignant (cancerous).

Types of Thyroid Cancer

Papillary Thyroid Cancer

Most people with thyroid cancer have papillary thyroid cancer. This type of tumor grows slowly. It usually starts in one lobe of the thyroid. Although it can spread to other parts of the body, it's usually treatable.

Follicular Thyroid Cancer

Fewer people have follicular thyroid cancer than papillary thyroid cancer. This type of thyroid cancer tends to grow slowly. When it's treated the right way, it can often be cured.

Hurthle Cell Carcinoma

This is a rare form of follicular thyroid cancer.

Medullary Thyroid Carcinoma (MTC)

MTC usually appears in older adults and affects one of the thyroid's two lobes. It starts in the parafollicular C cells of the thyroid gland and increases serum calcitonin levels.

Anaplastic Carcinoma

This type of thyroid cancer is sometimes called undifferentiated carcinoma. The disease usually develops from a papillary thyroid cancer or follicular thyroid cancer that's in the body already. It spreads quickly throughout the neck and other parts of the body.