Evaluation of the thyroid nodule

The annual incidence of thyroid cancer worldwide is 1 case per 100 000 men and 2.6 cases per 100 000 women. Most thyroid nodules are asymptomatic and are discovered incidentally on physical examination, self-palpation or incidentally on imaging studies performed for unrelated reasons. Although the majority of both palpable and non-palpable thyroid nodules are benign, approximately 5% may represent thyroid cancer. Thyroid-stimulating hormone, thyroid ultrasound and fine-needle aspiration biopsy are key tests to guide management. Physicians caring for patients with thyroid nodules need to develop a rational, cost-effective approach to ordering and interpreting imaging and diagnostic tests in the evaluation of the thyroid nodule.