Medullary carcinoma of the thyroid is cancer of the thyroid gland that starts in cells that release a hormone called calcitonin. These cells are called "C" cells. The thyroid gland is located inside the front of your lower neck.
The cause of medullary carcinoma of the thyroid (MTC) is unknown.
Unlike other types of thyroid cancer, MTC is less likely to be caused by radiation therapy to the neck given to treat other cancers during childhood.
There are two forms of MTC:
- Sporadic MTC, which does not run in families. Most MTCs are sporadic. This form mainly affects older adults.
- Inherited MTC, which runs in families.
You have an increased risk of this type of cancer if you have:
- A family history of MTC
- A family history of multiple endocrine neoplasia (MEN)
- A prior history of pheochromocytoma, mucosal neuromas, or hyperparathyroidism
Other types of thyroid cancer include:
Exams and Tests
Your health care provider will perform a physical exam. Lymph nodes in the neck may be swollen. Examination of the thyroid may reveal single or multiple nodules (lumps). Thyroid function tests (drawn from the blood) are usually normal.
Other tests that may be used to diagnose MTC may include:
Patients with MTC should be checked for certain other tumors, especially pheochromocytoma.
Treatment involves surgery to remove the thyroid gland and surrounding lymph nodes. Because this is an uncommon tumor, surgery should be performed by a surgeon who is familiar with this type of cancer and experienced with the operation required.
Chemotherapy and radiation do not work very well for this type of cancer. Radiation is used in some patients after surgery. New treatments are being investigated in clinical trials. Your doctor can tell you more about these, if needed.
Approximately 86% of those with medullary carcinoma of the thyroid live at least 5 years after diagnosis. The 10-year survival rate is 65%.
Complications may include:
- Cancer spreads to other areas of the body
- Parathyroid glands are accidentally removed during surgery
When to Contact a Medical Professional
Call your health care provider if you have symptoms of medullary carcinoma of the thyroid.
Prevention may not be possible. However, being aware of your risk factors, especially your family history, may allow for early diagnosis and treatment. For persons who have a very strong family history of MTC, the option to remove the thyroid gland may be recommended. You should carefully discuss this option with a doctor who is very familiar with the disease.
Thyroid - medullary carcinoma; Cancer - thyroid (medullary carcinoma); MTC
Schneider DF, Mazeh H, Lubner SJ, et al. Cancer of the endocrine system. In: Niederhuber JE, Armitage JO, Doroshow JH, et al., eds. Abeloff's Clinical Oncology. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2013:chap 71.
National Cancer Institute: PDQ Thyroid Cancer Treatment. Bethesda, Md: National Cancer Institute. Date last modified: 2/28/2014. Available at: http://cancer.gov/cancertopics/pdq/treatment/thyroid/HealthProfessional.Accessed: March 23, 2014.National Cancer Institute: PDQ Thyroid Cancer Treatment. Bethesda, Md: National Cancer Institute. Date last modified: 2/28/2014. Available at: http://cancer.gov/cancertopics/pdq/treatment/thyroid/HealthProfessional. Accessed: March 23, 2014.
National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Thyroid Carcinoma. Version 2.2013. Available at: http://www.nccn.org/professionals/physician_gls/PDF/thyroid.pdf.Accessed March 23, 2014.National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Thyroid Carcinoma. Version 2.2013. Available at: http://www.nccn.org/professionals/physician_gls/PDF/thyroid.pdf. Accessed March 23, 2014.
Update Date 3/23/2014
Updated by: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.