Nodular goiter is a highly prevalent disease in iodine-deficient areas. Usually nodule assessment includes ultrasonography (US) and fine-needle aspiration (FNA), but some benign nodules can hardly be distinguished from carcinomas. Elastography measures tissue elasticity using sonography, as malignancy is related to stiffness of solid organs. The investigators have designed a study to evaluate the diagnostic accuracy of elastography in nodular goiter. Consecutive patients will be assessed using US, FNA and elastography; the latter will be compared with cytology. Specificity, sensitivity, and predictive values will be calculated.