What is medullary thyroid cancer?

Medullary thyroid cancer makes up about 5% of all cases of thyroid cancer and is very different from the more common papillary and follicular thyroid cancers. Medullary thyroid cancer comes from the C-cells of the thyroid. The C-cells make a hormone called calcitonin which has a weak effect on bone growth and blood calcium levels. Since calcitonin's effect is so weak, it does not need to be replaced after removal of the thyroid like thyroid hormone. Fortunately, blood calcitonin levels can be used in making the diagnosis and to look for recurrences of medullary thyroid cancer. Unlike most other thyroid cancers, medullary thyroid cancer does not absorb RAI and therefore the best chance of curing a patient is completely removing the cancer at the first operation.

Medullary thyroid cancer (MTC) is a rare form of thyroid cancer and accounts for 3 to 10% of all thyroid cancers. MTC grows from specialized thyroid cells called parafollicular cells, or C-cells that make a hormone called calcitonin. Calcitonin helps control bone formation and blood calcium levels, but its action in humans is not very powerful. Unlike thyroxine (T4), calcitonin does not need to be replaced in adults if the thyroid is removed. Calcitonin can be used to make the diagnosis and as a marker of recurrent disease in patients with MTC. C-cells, unlike other cells in the thyroid, do not concentrate iodine and therefore MTC does not respond to radioactive iodine therapy. 

Medullary thyroid cancer is one form of cancer of the thyroid gland. The disease begins in the parafollicular cells, or C cells, which release calcitonin, a hormone that works to regulate the amount of calcium in the blood. Medullary thyroid cancer causes these C cells to multiply quickly and form a growth or tumor on the thyroid gland. This type of cancer can spread to other parts of the body.

There are two types of medullary thyroid cancer: sporadic and inherited. Sporadic medullary thyroid cancer is more common and mostly affects senior citizens. This type of cancer is not hereditary. Inherited medullary thyroid cancer, however is hereditary. People with a family history of the disease are more at risk.

Continue Learning about Medullary Thyroid Cancer

What are the symptoms of medullary thyroid cancer?
James Lee, MDJames Lee, MD
Most medullary thyroid cancers do not cause symptoms (i.e. they are asymptomatic). In fact, many pat...
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Is there a cure for medullary thyroid cancer?
Honor Society of Nursing (STTI)Honor Society of Nursing (STTI)
There is currently no cure for medullary thyroid cancer. The disease is treated by removing the thyr...
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Are there alternative treatments for medullary thyroid cancer?
Honor Society of Nursing (STTI)Honor Society of Nursing (STTI)
Because this form of cancer is so aggressive and the prognosis fairly poor, there are no currently k...
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What are the treatment options for medullary thyroid cancer?
American Association of Endocrine SurgeonsAmerican Association of Endocrine Surgeons
The best treatment for medullary thyroid cancer (MTC) is surgery to completely remove all disease in...
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