Fine-needle aspiration biopsy of thyroid nodules.

Nodular thyroid disease is a common problem, particularly in women and the elderly population. Furthermore, 5% of thyroid nodules are likely to be malignant. Therefore, assessment for malignant potential is important, and fine-needle aspiration (FNA) biopsy is the most accurate technique. For each nodule, two to four aspirations should be attempted from different areas of the nodule. Although major complications of FNA biopsy are rare, proper cytologic interpretation necessitates special expertise. Cytologic diagnoses are usually categorized as diagnostic or nondiagnostic, and the diagnostic specimens are classified as benign, "suspicious," or malignant. Rebiopsy is indicated for enlarging nodules, recurrent cysts, and nondiagnostic cytologic findings. Because FNA biopsy is a safe, reliable, and rapid means of evaluating thyroid nodules, we recommend its routine use for diagnosis and treatment of thyroid nodular disease.