Nontoxic goiter

What is this Condition?

Simple goiter is an enlargement of the thyroid gland - the butterfly-shaped gland in the front of the neck - that’s not caused by inflammation or abnormal growth of new tissue. Simple goiter is more common in women than men, especially during adolescence, pregnancy, and menopause, when the body’s demand for thyroid hormone increases. With appropriate treatment, the prognosis is good.

What Causes it?

Simple goiter occurs when the thyroid gland can’t secrete enough thyroid hormone to meet the body’s needs. To compensate, the thyroid gland enlarges. Such compensation usually overcomes mild to moderate hormonal deficiency. Goiter probably results from impaired hormone synthesis within the thyroid and depletion of the gland’s iodine level, which makes it more sensitive to thyroid-stimulating hormone .

Classifying Goiter

Simple goiter is commonly classified as endemic or sporadic. Endemic goiter usually results from too little iodine in the diet, as occurs from iodine-depleted soil or malnutrition. Using iodized salt prevents this deficiency.

Sporadic goiter is caused by eating large amounts of foods or taking drugs that decrease production of the thyroid hormone thyroxine. Such foods include rutabagas, cabbage, soybeans, peanuts, peaches, peas, strawberries, spinach, and radishes. Goiter-causing drugs include propylthiouracil (PTU), iodides, Butazolidin, Pabanol, cobalt, and Lithane. In a pregnant woman, such substances may cross the placenta and affect the fetus.

What are its Symptoms?

In simple goiter, the thyroid may be mildly enlarged, or it may be huge and misshapen. Simple goiter doesn’t affect metabolism, so the symptoms arise solely from the enlarged gland. The person’s neck may be swollen; if the gland compresses the windpipe and esophagus, difficulty breathing and swallowing may occur. A large goiter may impede blood flow through the veins, causing them to swell. Blocked veins may cause dizziness or fainting when the person raises his or her arms above the head.

How is it Diagnosed?

The doctor reviews the medical history and performs a physical exam to rule out disorders with similar symptoms, such as Graves’ disease, Hashimoto’s disease, and thyroid cancer. A detailed history also may reveal goiter-causing foods or medications or geographic factors.

Lab test results that suggest goiter include:

• a normal-to-high level of thyroid-stimulating hormone

• low-normal or normal thyroxine levels

• normal or increased uptake of radioactive iodine

How is it Treated?

The goal of treatment is to reduce an enlarged thyroid. The treatment of choice is thyroid hormone replacement with Levoid, a preparation that inhibits secretion of thyroid-stimulating hormone and allows the gland to rest. Small doses of iodide commonly relieve goiter caused by iodine deficiency. A person with sporadic goiter must avoid goiter-causing drugs and foods.

For a large goiter that doesn’t respond to treatment, the surgeon may have to remove part of the thyroid.