[Thyroid nodules: clinical management and differential diagnosis].

Thyroid nodules are common and are frequently benign. The prevalence of thyroid nodules ranges from 3-7% (palpation) to 50% (ultrasonography). Thyroid cancer occurs in 5-10% of nodules. Thyroid ultrasonography (US) is not a screening test but all patients with palpable thyroid nodule should undergo US examination. US-guided fine-needle aspiration citology (FNC) is recommendend for nodules with suspicious features at US examination or when clinical risk factors occur. A radioisotope scan is useful if the TSH is low or suppressed to detect (benign) functioning nodules.