General Principles

• The evaluation of goiter is based on palpation of the thyroid and evaluation of thyroid function. If the thyroid is enlarged, the examiner should determine whether the enlargement is diffuse or nodular. Both forms of goiter are common, especially in women.
• Thyroid scans and ultrasonography do not provide additional useful information about goiters that are diffuse by palpation and should not be performed in these patients. In contrast, all palpable thyroid nodules should be evaluated by ultrasonography.
• In rare patients, more commonly in those with MNG, the gland compresses the trachea or esophagus and causes dyspnea or dysphagia, necessitating treatment. Thyroxine treatment has little, if any, effect on the size of MNGs. Subtotal thyroidectomy is most commonly used to relieve compressive symptoms. RAI therapy will reduce gland size and relieve symptoms in most patients if surgery is not an option, though much higher doses are necessary if the patient is euthyroid.
• Diffuse goiter
  • Almost all euthyroid diffuse goiters in the US are due to chronic lymphocytic thyroiditis (Hashimoto thyroiditis). This diagnosis can be confirmed by measurement of antithyroid peroxidase antibodies. Because Hashimoto thyroiditis may also cause hypothyroidism, plasma TSH should be measured.
  • Diffuse euthyroid goiters are usually asymptomatic, and therapy is seldom required. Patients should be monitored regularly for the development of hypothyroidism.
  • Diffuse hyperthyroid goiter is most commonly because of Graves disease, and treatment of the hyperthyroidism usually improves the goiter (see “Hyperthyroidism” section).
• Nodular goiter
  • Between 30% and 50% of people have nonpalpable thyroid nodules that are detectable by ultrasound. These nodules rarely have any clinical importance, but their incidental discovery may lead to unnecessary diagnostic testing and treatment.
  • Nodules are more common in older patients, especially women, and 5%–10% of thyroid nodules are thyroid carcinomas.