Skip to Main Content

Key Features

Essentials of Diagnosis

  • Common in regions with low-iodine diets

  • High rate of congenital hypothyroidism and cretinism

  • Goiters may become multinodular and enlarge

  • Most adults with endemic goiter are euthyroid; however, some are hypothyroid or hyperthyroid

General Considerations

  • Cretinism occurs in up to 0.5% of iodine-deficient populations; less severe manifestations of congenital hypothyroidism more common

  • Causes

    • Iodine deficiency (most common)

    • Certain foods (eg, sorghum, millet, maize, cassava)

    • Mineral deficiencies (selenium, iron, zinc)

    • Water pollutants

    • Congenital partial defects in thyroid enzyme activity

  • Pregnancy aggravates iodine deficiency and can increase the size of thyroid nodules and cause new nodules

Clinical Findings

Symptoms and Signs

  • Thyroid may become multinodular and very large

  • Growth often occurs during pregnancy and may cause compressive symptoms

  • Substernal goiters usually asymptomatic but can cause

    • Tracheal compression

    • Respiratory distress

    • Dysphagia

    • Superior vena cava syndrome

    • Phrenic or recurrent laryngeal nerve palsy, or Horner syndrome

    • Gastrointestinal bleeding from esophageal varices

    • Pleural or pericardial effusions (rare)

  • Cerebral ischemia and stroke can result from arterial compression or thyrocervical steal syndrome

  • Malignancy in < 1%

  • Some patients with goiter become hypothyroid

  • Other patients become thyrotoxic as goiter grows and becomes more autonomous, especially if iodine added to diet

  • Congenital hypothyroidism

    • Isolated deafness

    • Short stature

    • Impaired mentation

Differential Diagnosis

  • Benign multinodular goiter

  • Pregnancy (in areas of iodine deficiency)

  • Graves disease

  • Hashimoto thyroiditis

  • Subacute (de Quervain) thyroiditis

  • Drugs causing hypothyroidism

    • Lithium

    • Amiodarone

    • Propylthiouracil

    • Methimazole

    • Phenylbutazone

    • Sulfonamides

    • Interferon-α

    • Iodide

  • Infiltrating disease, eg, malignancy, sarcoidosis

  • Suppurative thyroiditis

  • Riedel thyroiditis

Diagnosis

Laboratory Tests

  • Serum thyroxine and thyroid-stimulating hormone (TSH) usually normal

    • TSH low if multinodular goiter becomes autonomous in presence of sufficient iodine for thyroid hormone synthesis, causing hyperthyroidism

    • TSH high in hypothyroidism

  • Serum levels of antithyroid antibodies usually undetectable or low

  • Serum thyroglobulin often elevated above 13 mcg/L

Imaging Studies

  • Thyroid radioactive iodine uptake usually elevated, but may be normal if iodine intake has improved

Treatment

Medications

  • Dietary iodine supplementation (eg, addition of potassium iodide to table salt)

    • Greatly reduces prevalence of endemic goiter and cretinism but is less effective in shrinking established goiter

    • Has not proven effective for treating adults with large multinodular goiter and actually increases their risk of developing thyrotoxicosis

Surgery

  • Thyroidectomy indicated for cosmesis, compressive symptoms, or thyrotoxicosis in adults with very large multinodular goiters

Procedures

  • Patients may be treated with 131I for large compressive goiters

Outcome

Follow-Up

  • Partial thyroidectomy is followed by a high goiter recurrence rate in iodine-deficient geographic areas, so total thyroidectomy is preferred when surgery is indicated

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.