The thyroid gland is a small endocrine gland located in the front of the neck. It consists of two lobes connected by a thin band of tissue called the isthmus. The thyroid is made up of follicles, which are lined with cells that secrete hormones that helps the body with many metabolic functions. Thyroid cancer arises when these cells start to malfunction. The most important risk factor for development of thyroid cancer is previous radiation to the area.
Papillary thyroid cancer is the most common type, comprising over 80% of all thyroid cancers, and often occur in young women. They are the most slow growing and respond very well to treatment.
Follicular thyroid cancer, similar to the papillary type, is generally slow-growing and responsive to treatment. Together they make up what we consider to be well-differentiated thyroid cancers, which means that the cancer cells look and function similarly to regular cells. One of its subvariants called the Hurthle cell variant can have a poor prognosis overall.
Medullary thyroid cancer is an uncommon type of thyroid cancer, comprising about 5% of all thyroid cancers. They most often develop in adults in their 50s and 60s. While most occur spontaneously by chance, there can be some genetic basis to developing medullary thyroid cancer, and those who do present with an inheritance pattern to this diagnosis can present with concurrent endocrine conditions.
Anaplastic thyroid cancer is a rare type of thyroid cancer, and acts very aggressively as it grows and spreads quickly. The cancer cells of this thyroid cancer subtype are very undifferentiated, meaning that they look and behave very differently from regular thyroid cells.
There are several surgical options for thyroid malignancies. A lobectomy involves removing one side, or lobe, of the thyroid. This is usually indicated for less aggressive types of thyroid cancer or those that are small and localized without having spread.
Thyroidectomy involves the complete removal of the thyroid, and is the most common type of surgery done for thyroid cancer. For cancers that have spread further, neck dissection can be considered, wherein in addition to removal of the thyroid, lymph nodes and other tissues around the thyroid can be removed. En bloc resection involves the resection of the thyroid tumor, lymph nodes, surrounding tissue, and other neck structures as one piece. This can be quite significant and may require extensive reconstruction depending on the extent of the disease.
Like other cancers, thyroid cancers can also be managed with radiation therapy, chemotherapy, and targeted pharmacological agents. Often patients will require hormonal therapy with synthetic thyroid hormone to make up for the lower levels of endogenous hormone produced.
More information on thyroid cancer at the following links:
Canadian Cancer Society
Thyroid Foundation of Canada
Thyroid Cancer Canada