goiter

Introduction

Enlargement of the thyroid gland.

Etiology

• iodine deficiency is most common cause worldwide
• autoimmune thyroiditis
  • Hashimoto's thyroiditis
  • Riedel thyroiditis (IgG4 disease-related)

History

• iodine intake
• rate of change in size
• thyroid cancer risk factors (radiation exposire, family history)

Clinical manifestations

• enlargement of the thyroid gland

Laboratory

• thyroid function testing
  • serum TSH (all patients)
    • if low, free T4 & serum T3 (+ thyroid scintigraphy)
    • if normal or high, thyroid ultrasound (see Radiology)

Diagnostic procedures

• flow-volume-loop study in patients at risk for or with symptoms of airway obstruction (tracheal lumen < 1 cm in diameter)

Radiology

• ultrasound of thyroid (& neck)
  • serum TSH normal or high AND
    • risk factors for thyroid cancer, palpable thyroid nodules, thyroid gland asymmetry, large goiters, rapid growth or thoracic outlet syndrome
• thyroid scintigraphy if serum TSH is low
• avoid iodinated contrast to avoid precipitating iodine-induced hyperthyroidism

Complications

• compression of adjacent structures
  • thoracic outlet syndrome
  • compression of trachea
• hyperthyroidism or hypothyroidism

Management

• replacement of thyroid hormone to suppress elevated serum TSH
• thyroid surgery (surgical resection)

More general terms

• sign/symptom
• thyroid disease

More specific terms

• diffuse goiter; simple goiter; colloid goiter
• multinodular goiter