ABSTRACT
This chapter focuses on nodular thyroid disease includes a discussion on the prevalence and pathogenesis of thyroid nodules. A thyroid nodule is a discrete lesion within the thyroid caused by an excess proliferation of cells compared to the surrounding normal thyroid parenchyma. The incidence of goiter, either due to iodine deficiency or environmental goitrogens, varies with the geographic region examined. Iodine deficiency is the most common worldwide etiology of goiter. Patients may present with symptoms such as a lump or swelling in the neck, hoarseness of voice, neck pressure or pain, cough, dyspnea, or dysphagia. US is the primary imaging modality recommended to confirm the presence of a nodule, to document the presence of other more clinically significant nodules, to identify suspicious sonographic features in nodules, and to document the presence of abnormal regional adenopathy.
