Medullary carcinoma of thyroid

Definition

Medullary carcinoma of the thyroid is a malignancy of the thyroid gland arising from the C cell, which secretes the hormone calcitonin.

Causes, incidence, and risk factors

The cause is unknown, but is not thought to be related to radiation therapy, as opposed to other thyroid cancers. Thyroid function tests are usually normal. Risk factors are a family history of multiple endocrine neoplasia (MEN), a prior history of pheochromocytoma, mucosal neuromas, or hyperparathyroidism.

The average age at diagnosis is the mid-40s, except in patients with inherited cancer syndromes, in which the cancer often occurs earlier. Approximately 700 new cases are diagnosed each year in the United States. The condition runs in the family about 20% of the time.

Other types of thyroid cancer are papillary carcinoma of the thyroid, anaplastic carcinoma of the thyroid, follicular tumor of the thyroid, thyroid lymphoma, and metastatic thyroid cancer.

Symptoms

• Firm thyroid mass
• Goiter
• Diarrhea
• Cough
• Cough with blood

Signs and tests

• A physical examination reveals enlarged cervical lymph nodes.
• An examination of the thyroid reveals single or multiple nodules.
• A thyroid biopsy shows medullary carcinoma of thyroid cells.
• An ultrasound of the thyroid reveals a nodule.
• A thyroid scan shows a cold nodule (one that does not light up on scan).
• The calcitonin level is elevated.

Treatment

Surgical removal of the thyroid gland, as well as surrounding lymph nodes, is the initial treatment. Chemotherapy and radiation are not very effective.

The risks of surgery include accidental removal of parathyroid glands or nerve tissue of the larynx, which leads to serious complications.

Support Groups

For additional resources, see cancer support group.

Expectations (prognosis)

The expectation for this type of thyroid cancer varies, depending on the removal of all cancerous tissue. The 10-year survival rate (percentage of people who live at least 10 years after diagnosis) is 70 - 80%.

Complications

• Medullary carcinoma invading nearby lymph nodes
• Inadvertent removal of parathyroid glands during surgery
• Metastasis of cancer to blood vessels or other sites

Calling your health care provider

Call for an appointment with your health care provider if symptoms of this disorder develop.

Prevention

Prevention may not be possible. However, being aware of your risk factors, especially a family history, may allow early diagnosis and treatment.

Illustrations

Thyroid cancer - CT scan

Thyroid gland

Page Content:

Thyroid - medullary carcinoma; Cancer - thyroid (medullary carcinoma) ; medullary thyroid carcinoma