Thyroid nodules.

According to the literature, thyroid nodules (TNs) are quite rare in the first two decades of life and are predominantly non-cancerous, although cancerous TNs are more common in the first two decades of life than in adults. Therefore, it is important for clinicians to distinguish benign from malignant lesions preoperatively because the latter require a total thyroidectomy with or without neck lymph node dissection. A careful work-up and a fine-needle aspiration biopsy (FNAB) are mandatory to improve the preoperative diagnosis. High-resolution thyroid ultrasound and real-time elastosonography are adjuvant presurgical tools in selecting patients for surgery, particularly those with indeterminate or non-diagnostic cytology. Elevated thyroid-stimulating hormone (TSH) level in a patient with a thyroid nodule is a new laboratory predictor of thyroid cancer risk. The majority of thyroid carcinomas derive from the follicular cell, whereas medullary thyroid carcinoma (MTC) derives from calcitonin-producing cells. Patients with MTC are screened for germ-line RET mutations to detect carriers and identify family members for prophylactic or therapeutic thyroidectomy.