Thyroid Cancer Diagnosis Medullary Carcinoma

Medullary thyroid cancer, also called “medullary carcinoma” or “medullary thyroid carcinoma,” is the third most common form of thyroid cancer, accounting for 5 to 10 percent of thyroid cancer cases each year. Medullary thyroid cancer originates in the C cells, also called “parafollicular cells.” C cells produce calcitonin, a hormone that regulates calcium metabolism.

As with other forms of thyroid cancer, the main medullary thyroid cancer symptoms are lumps in the throat and, if the disease has advanced, hoarseness and trouble breathing.

Types of Medullary Thyroid Cancer

Medullary carcinoma can occur in three different contexts:

  • Inherited: Occurs in patients with a family history of the disease; this is the least aggressive form of the disease.
  • Multiple Endocrine Neoplasia Syndromes (MEN 2A and MEN 2B): Includes medullary carcinoma as one of three in a group of endocrine disorders. It can be inherited or sporadic.
  • Sporadic: This accounts for 80 percent of all cases. Patients with the sporadic form of the disease have no family history of thyroid cancer and no symptoms of other endocrine disorders.

Women are more likely to develop sporadic medullary carcinoma in the thyroid; the other forms affect women and men equally.

Treating Medullary Carcinoma of the Thyroid

A complete thyroidectomy — removal of the thyroid gland — is usually recommended for patients with medullary thyroid cancer. In addition, all lymph nodes and fatty tissues in the central area of the neck and in the tumor side of the neck will likely be removed during surgery.

Because the C cells aren’t thyroid cells, they won’t absorb iodine, making the radioactive iodine treatments used in other thyroid cancers ineffective. Sometimes doctors use radiation and chemotherapy to improve thyroid cancer symptoms that may persist after surgery.

Follow-Up Procedures and Tests

Along with customary cancer check-ups, patients with medullary carcinoma will likely receive a yearly chest x-ray and have their calcitonin levels measured. Since the C cells in the thyroid are the only cells in the body that make this hormone, calcitonin levels need to be checked regularly to make sure surgery has removed all of the cancerous C cells. An elevated level of calcitonin in the body post-surgery usually indicates cancer recurrence.

The National Cancer Institute recommends checking calcitonin levels every 4 months for the first few years, and every 6 months after that.

Prognosis for Medullary Thyroid Carcinoma

Medullary thyroid cancer has a lower cure rate than papillary and follicular thyroid cancers, but the prognosis is better if the disease is caught early on and if it hasn’t spread to distant organs, such as the liver or brain. When medullary carcinoma is confined to the thyroid, 90 percent of patients have a 10-year survival rate. The number declines to 70 percent if the cancer reaches the lymph nodes in the neck and 20 percent if the cancer metastasizes to distant areas.

The most challenging cases usually occur in men over age 50 with distant spread of the disease and other endocrine tumors.

Resources

MedicineNet.com Staff. (n.d.). Thyroid cancer. Retrieved March 23, 2010, from the MedicineNet.com Web site: http://www.medicinenet.com/thyroid_cancer/article.htm.

National Cancer Institute Staff. (n.d.). What you need to know about thyroid cancer. Retrieved March 23, 2010, from the National Cancer Institute Web site: http://www.cancer.gov/cancertopics/wyntk/thyroid/page9.

American Thyroid Clinic Staff. (n.d.). Medullary thyroid cancer. Retrieved March 23, 2010, from the American Thyroid Clinic Web site: http://www.thyroidcancer.com/medullary_thyroid_cancer.htm.

Norman, J. (2010). Thyroid cancer: Medullary cancer: The third most common thyroid cancer. Retrieved March 23, 2010, from the Endocrineweb.com Web site: http://www.endocrineweb.com/camed.html.