The thyroid is a butterfly-shaped, small gland at the neck’s base. Thyroid cancer occurs when cancer develops in the thyroid gland. The thyroid gland produces hormones that aid in metabolism. They also help control heart rate, blood pressure, and body temperature. Fortunately, thyroid cancer is highly treatable. There are different types of thyroid cancer, and the doctors suggest a treatment plan based on the type and stage. This article lists the various types of thyroid cancer.

1. Differentiated thyroid cancers
It is a broad category that encompasses thyroid cancer that originates in the cells responsible for storing and producing thyroid hormones. Such cells are known as follicular cells. The cancer cells in such cancers look like healthy cells when viewed under a microscope. Below are some cancers in this category.

• Papillary thyroid cancer
  It is the most prevalent type of thyroid cancer. Approximately 80–85 percent of people with thyroid cancer have papillary carcinoma. It is a slow-growing cancer that originates from the follicular cells, usually in one, but sometimes in both of the thyroid glands’ lobes. Papillary thyroid cancer can spread to the lymph nodes in the neck. However, the patient may have a good prognosis with a comprehensive treatment plan.
• Follicular thyroid cancer
  It is the second-most common thyroid cancer type. Follicular carcinoma is prevalent in countries with insufficient iodine intake in their meals. Usually, the treatment ensures a good prognosis, but follicular thyroid cancer is more aggressive than papillary carcinoma. However, this cancer does not typically advance to the surrounding lymph nodes, but it has a greater risk (than papillary cancers) of spreading to bones and lungs.
• Hurthle cell cancer
  Also called oncocytic thyroid cancer, Hurthle cell carcinoma was earlier grouped with follicular thyroid cancers, given the many similarities. It is a rare type, and less than 5 percent of all thyroid cancers are Hurthle cell thyroid cancer. This cancer is mainly diagnosed in people over 40 and is relatively more prevalent in women.

2. Poorly differentiated thyroid cancer
It comprises a group of rare and more aggressive thyroid cancers. Such cancers also do not respond to the usual treatment measures. Some prevalent types include the following:

• Anaplastic thyroid cancer
  It is a rare thyroid cancer that spreads quickly and is challenging to cure, but the correct measures can help lower its progression. Anaplastic thyroid carcinoma is most common in people over 60 and can result in severe symptoms, such as neck swelling that aggravates very rapidly and may cause difficulty swallowing and breathing. Only 2–3 percent of all thyroid cancer cases report this cancer.
• Medullary thyroid cancer
  This rare thyroid cancer begins in the C thyroid cells. The C cells are responsible for hormone calcitonin production. When the blood shows high calcitonin levels, it hints at an early stage of medullary thyroid cancer. Usually, such cancers stem from an RET gene children inherit from their parents. Modifications in the RET gene can also result in Type 2 multiple endocrine neoplasia and familial medullary thyroid cancer. The latter aggravates the susceptibility to thyroid cancer, and the former amplifies the risk of adrenal gland cancer, thyroid cancer, and other cancers. Approximately 4–10 percent of all thyroid cancer cases belong to this category.

3. Other rare types
Other rare thyroid cancer types begin in the thyroid gland. These include thyroid lymphoma (that starts in the gland’s immune system cells) and thyroid sarcoma (that begins in the thyroid’s connective tissue).