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Endocrine glands


Thyroid enlargement - scintiscan


Thyroid gland

Colloid nodular goiter

Definition

Colloid nodular goiter is the enlargement of an otherwise normal thyroid gland.

Alternative Names

Endemic goiter

Causes

Colloid nodular goiters are also known as endemic goiters. They are usually caused by not getting enough iodine in the diet.

Colloid nodular goiters tend to occur in certain areas with iodine-poor soil. These areas are usually away from the sea coast. An area is defined as endemic for goiter if more than 10% of children ages 6 - 12 have goiters.

Certain things in the environment may also cause thyroid enlargement.

Small- to moderate-sized goiters are relatively common in the United States. The Great Lakes, Midwest, and Intermountain regions were once known as the "goiter belt." The routine use of iodized table salt now helps prevent this deficiency.

Risk factors for colloid nodular goiters include:

Being over age 40
Being female
Having a family history of goiter
Living in an area where there is endemic iodine deficiency
Not getting enough iodine in your diet

Symptoms

Breathing difficulties (rare)
Dizziness when the arms are raised above the head (large goiter)
Enlarged neck veins
Swallowing difficulties (rare)
Thyroid swelling (nodule)

Exams and Tests

Blood tests to monitor thyroid function, including thyroid stimulating hormone (high if underactive, low if overactive)
Radioactive iodine uptake (normal or increased)
Thyroid scan
Thyroid ultrasound
Urinary excretion of iodine (low)

Treatment

Thyroid hormone replacement therapy is prescribed for iodine deficiency. If you can increase the iodine content of your diet, you may no longer need thyroid hormone replacement therapy.

You may need surgery to remove all or part of the thyroid gland if you have a large goiter that doesn't go away with treatment or that restricts swallowing and breathing.

If the goiter is producing too much thyroid hormone, treatment may be needed with:

Antithyroid medication
Radioactive iodine
Surgery

Outlook (Prognosis)

The outlook is good with treatment. A persistent goiter may become toxic. This can cause symptoms of excess thyroid hormones.

Sudden enlargement of a thyroid gland may mean there is internal bleeding or an immune disorder. It requires immediate medical attention.

Possible Complications

When to Contact a Medical Professional

Call your health care provider if you have signs of thyrotoxicosis:

Prevention

Use iodized salt or foods supplemented with iodine.

Review Date: 6/17/2008
Reviewed By: Elizabeth H. Holt, MD, PhD, Assistant Professor of Medicine, Section of Endocrinology and Metabolism, Yale University. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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