Types of thyroid cancer
A) Papillary thyroid cancer
Papillary thyroid cancer is the most common type of thyroid cancer, accounting for approximately 80 percent of all cases. It is slow growing and usually presents as a single lump or nodule. Papillary thyroid cancer is often treated with surgery to remove the affected tissue, followed by radioactive iodine therapy to destroy any remaining cancer cells.
The prognosis of papillary thyroid cancer is better than other types of cancer, and it grows in the epithelial tissue of the thyroid gland. This type of cancer is usually found as a solid mass, but in rare cases, doctors can find it as a cyst or fluid-filled sac.
B) Follicular thyroid cancer
Follicular thyroid cancer is the second most common type of thyroid cancer, making up approximately 10 to 15 percent of cases. It is often found as a single lump or nodule and is usually treated with surgery to remove the affected tissue, followed by thyroid hormone therapy.
Together with papillary thyroid cancer, it makes up 95% of the cases of thyroid cancer. Similar to papillary thyroid cancer, it has a somewhat good prognosis because it is a highly differentiated type of tumor. However, around 11% of patients may have metastases at the moment of the diagnosis, and the prognosis is better in younger patients.
C) Medullary thyroid cancer
Medullary thyroid cancer is the third most common form of thyroid cancer, making up approximately 3 to 4 percent of cases. It is often found as a single lump or nodule and is usually treated with surgery to remove the affected tissue, followed by chemotherapy and/or radiation therapy.
Medullary thyroid cancer grows in the inside of the thyroid gland, in an area known as medulla. This area of the thyroid contains parafolicular C cells, which produce thyroid hormone. If the tumor starts to release thyroid hormone right away, patients will start to experience symptoms. Otherwise, symptoms will start when the nodule is big and causes obstruction.
D) Anaplastic thyroid cancer
Anaplastic thyroid cancer is the rarest and most aggressive form of thyroid cancer, making up 2 percent of cases in the United States, and sometimes less than that. It is also found as a single lump or nodule in most cases, and the treatment is similar, with chemotherapy or radiation therapy, sometimes a combination of both.
It is an undifferentiated carcinoma of the thyroid gland, which means that anaplastic thyroid cancer contains highly mutated cells. Since these cells undergo several mutations, this type of cancer is often more aggressive and difficult to treat. The prognosis is very poor, with a mortality close to 100% because most patients already have metastasis at the moment of diagnosis.