Fine needle aspiration of the thyroid gland

Fine needle aspiration (FNA) has become a major diagnostic triage for clinical management of patients with a thyroid mass. Diagnostic accuracy of this procedure can be evaluated by cyto-histologic correlation. Out of 1,761 fine needle aspirates of thyroid glands performed from January 1996 to December 1999, 230 satisfactory specimens contained respective histologic correlates. Using histologic diagnoses as the gold standard, the overall accuracy, sensitivity and specificity for cytologic diagnoses of thyroid neoplasm were 90.4 per cent, 85.7 per cent, and 92.5 per cent respectively. The positive predictive value for diagnosing thyroid neoplasm was 83.3 per cent while the negative predictive value was 93.7 per cent. The common pairs of cyto-histological diagnostic discrepancy included adenomatous goiter vs follicular neoplasm, adenomatous goiter vs papillary carcinoma, and thyroiditis vs follicular neoplasm. In conclusion, FNA is a rapid, reliable and safe diagnostic tool to distinguish non-neoplastic from neoplastic lesions in patients with thyroid masses.