by Carson-DeWitt R

Cancer is a disease in which cells grow in an uncontrolled way. If cells keep dividing, a mass of tissue called a tumor forms.

A tumor can be benign or malignant. A benign tumor is not cancer and will not spread to other parts of the body. A malignant tumor is cancer. Cancer cells invade and damage tissue around them. They can also enter the lymph and blood streams, spreading to other parts of the body. Thyroid cancer is the development of cancer cells in the thyroid gland.

Cancer Cell Growth
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Normal Anatomy and the Development of Thyroid Cancer

The thyroid is a butterfly-shaped gland located in the lower neck. The thyroid makes and releases chemicals called hormones. These hormones regulate certain body functions. They can affect major body structures like the heart, brain, and muscles. The thyroid gland needs iodine to work properly. Iodine comes from food.

Cancer growth in the thyroid can interfere with how the thyroid works. A tumor can press on nearby structures. If it grows beyond the thyroid, the cancer can invade the nearby voice box and windpipe. This growth can make it difficult to speak or breathe. If cancer cells reach nearby lymph nodes or blood vessels, it can spread to other parts of the body. Common sites for thyroid cancer to spread to are:

  • Lymph nodes in other parts of the body
  • The bones and lungs

The Thyroid
The Thyroid
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Types of Thyroid Cancer

There are different types of thyroid cancer. They are based on the specific types of cells where the cancer starts. Types of thyroid cancer include:

  • Differentiated—Appear like normal thyroid cells under a microscope. They may be:
    • Papillary—Makes up nearly all thyroid cancers. This type tends to grow more slowly than other types. It is more easily treated.
    • Follicular—Second most common type. It is often linked to low iodine levels or exposure to radiation.
  • Medullary—Rare type that starts in cells that produce calcitonin. This type is more aggressive and harder to find. It often spreads beyond the thyroid before it is found. Subtypes include sporadic and familial (inherited).
  • Anaplastic—Rare type that is aggressive and fast growing. It usually spreads beyond the thyroid gland before it is found.

References

Anaplastic thyroid cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/anaplastic-thyroid-cancer. Accessed April 20, 2022.

Follicular thyroid cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/follicular-thyroid-cancer-21. Accessed April 20, 2022.

Medullary thyroid cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/medullary-thyroid-cancer. Accessed April 20, 2022.

Papillary thyroid cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/medullary-thyroid-cancer. Accessed April 20, 2022.

Stages of thyroid cancer. National Cancer Institute website. Available at: https://www.cancer.gov/types/thyroid/patient/thyroid-treatment-pdq#section/%5F27. Accessed April 20, 2022.

Tests for thyroid cancer. American Cancer Society website. Available at: https://www.cancer.org/cancer/thyroid-cancer/detection-diagnosis-staging/how-diagnosed.html. Accessed April 20, 2022.

Thyroid cancers. Merck Professional Version website. Available at: http://www.merckmanuals.com/professional/endocrine-and-metabolic-disorders/thyroid-disorders/thyroid-cancers. Accessed April 20, 2022.

Treatment option overview. National Cancer Institute website. Available at: https://www.cancer.gov/types/thyroid/patient/thyroid-treatment-pdq#section/%5F67. Accessed April 20, 2022.

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