Nontoxic Nodular Goiter
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Nontoxic Nodular Goiter

(Sporadic Goiter; Simple Goiter; Nodular Enlargement of the Thyroid Gland )

En Español (Spanish Version)

Definition

A goiter is an enlargement of the thyroid. The thyroid is an endocrine gland that produces hormones that help regulate your body’s metabolism. It is located on the front of the neck, right below the “Adam’s apple.” Goiters are seldom painful and tend to grow slowly.

There are different types of goiters. A nontoxic (or sporadic) goiter is a type of “simple” goiter that may be diffuse (enlarging the whole thyroid gland) or nodular (enlargement caused by nodules, or lumps, on the thyroid.) The development of nodules marks a progression of the goiter and should be evaluated by your doctor.

Goiter (Enlargement of the Thyroid Gland)

© 2008 Nucleus Medical Art, Inc.

Causes

The exact causes of nontoxic goiter are not known. In general, goiters may be caused by underproduction or overproduction of thyroid hormones. However, a nontoxic goiter is usually characterized by normal thyroid function. Some possible causes of nontoxic goiter include:

  • Heredity (family history of goiters)
  • Regular use of medications such as lithium, propylthiouracil, phenylbutazone, or aminoglutethimide
  • Regular intake of substances (goitrogens) that inhibit production of thyroid hormone—Some common goitrogens include foods such as cabbage, turnips, brussel sprouts, seaweed, and millet.
  • Iodine deficiency—Iodine deficiency is very rare in the US and other developed countries, due to the use of iodized table salt. However, iodine deficiency is a primary cause of goiter in other parts of the world, particularly in mountainous areas, or areas that experience heavy rainfall or flooding.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. The following factors increase your chance of developing nontoxic goiter.

  • Sex: female (Nontoxic goiter is more common in women than men.)
  • Age: over 40 years

If you have any of these risk factors, tell your doctor:

  • Family history of goiter
  • History of radiation therapy to head or neck, especially during childhood

Symptoms

Nontoxic goiters usually do not produce noticeable symptoms. However, if you experience any of the symptoms below, do not assume it is due to nontoxic goiter. These symptoms may be caused by other, less serious health conditions. If these symptoms persist, see your physician.

  • Swelling on the neck
  • Breathing difficulties, coughing, or wheezing with large goiter
  • Difficulty swallowing with large goiter
  • Feeling of pressure on the neck
  • Hoarseness

Diagnosis

Your doctor will ask about your symptoms and medical history, and perform a physical exam. If you are diagnosed with nontoxic nodular goiter, you should consult an endocrinologist.

Tests may include the following:

  • Examination of the neck—to assess any thyroid enlargement
  • Ultrasound —a test that uses sound waves to identify nodules of the neck and thyroid
  • Blood tests—to assess levels of thyroid hormones (eg, thyroid stimulating hormone). Thyroid autoantibodies tests may also be done.
  • Thyroid scan (scintigraphy)—a picture of your thyroid gland taken after you have been given a shot or drink of a radioisotope. The scan will show how your thyroid is functioning and used to exclude thyroid cancer .
  • Fine needle aspiration biopsy —a small needle will be inserted into a nodule in the thyroid to obtain a tissue sample. The sample will be examined to determine if it is benign or malignant (cancer). In 50%-60% of all biopsies taken, the results are noncancerous.
  • Barium swallow —a test to determine if the enlarged goiter is compressing the esophagus, thus causing swallowing difficulty
  • X-ray of neck and chest for large goiters—to see if the trachea is compressed

Treatment

Nontoxic goiters usually grow very slowly and may not cause any symptoms, and thus may not require treatment. However, if the goiter grows rapidly, or you have symptoms that affect your neck or obstruct your breathing functions, treatment may be required. If a nontoxic goiter progresses to the nodular stage, and the nodule is found to be cancerous, you will need treatment. Talk with your doctor about the best treatment plan for you. Treatment options include the following:

Hormone Suppression Therapy

This type of treatment works by using thyroid hormone medication to suppress secretion of thyrotropin (TSH). TSH is the thyroid-stimulating hormone that causes growth of the thyroid gland. Hormone suppression therapy is most effective for early stage goiters that have grown due to impaired hormone production. (It is less effective for goiters that have progressed to the nodular stage.) If nodules continue to grow during treatment, the thyroid gland may need to be surgically removed.

Radioactive Iodine

Radioactive iodine treatment is used to reduce the size of large goiter in the elderly when surgical treatment is contraindicated.

Surgery

Thyroidectomy is a surgical procedure to remove a portion or all of the thyroid gland. It is the treatment of choice in someone whose nontoxic goiter is so large to cause difficulty in breathing or swallowing. This type of surgery should be performed by a thyroid surgeon.

Prevention

Be sure that your diet contains enough iodine, which is not a problem if you live in the US.

RESOURCES:

American Association of Clinical Endocrinologists
http://www.aace.com

The American Thyroid Association
http://www.thyroid.org

The Hormone Foundation
http://www.hormone.org

Thyroid Foundation of America
http://www.tsh.org

CANADIAN RESOURCES:

Canadian Family Physician
http://www.cfpc.ca/cfp/

Thyroid Foundation of Canada
http://www.thyroid.ca

References:

Bonnema SJ, Bennedbek FN, Ladenson PW, Hegedus L. Management of the nontoxic multinodular goiter: a North American Survey. J Clin Endocrinol Metab . 2002;87:112-117.

Bonnema SJ, Nielsen VE, et al. Improvement of goiter volume reduction after 0.3 mg recombinant human thyrotropin-stimulated radioiodine therapy in patients with a very large goiter: a double-blinded, randomized trail. J Clin Endo Metab. 2007;92:3424-428.

Diehl LA, Garcia V, Bonnema SJ, et al. Management of the nontoxic multinodular goiter in Latin America: comparison with North America and Europe, an electronic survey. J Clin Endocrinol Metab . 2005;90:117-123.

Freitas JE. Therapeutic options in the management of toxic and nontoxic nodular goiter. Seminars in Nuclear Medicine . 2000;30:88-97.

Hurley DL, Gharib H. Evaluation and management of multinodular goiter. Otolaryngol Clin North Am . 1996;29:527-540.

Kasper DL et al. Harrison’s Principles of Internal Medicine . 16th ed. New York, NY: McGraw-Hill; 2005.



Last reviewed March 2008 by David Juan, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.


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