Evaluation of fine needle aspiration (FNA) cytology in the diagnosis of thyroid nodules.

FNA cytology of 112 patients with thyroid nodules seen in a 5-year period in a general hospital setting, and the histology obtained from the 53 operated patients, were retrospectively analysed. The inadequacy rate of FNA cytology was 11%, sensitivity was 84% (16/19), specificity was 52% (15/29), positive predictive value was 53% (16/30) and negative predictive value was 83% (15/18). Extrapolating these figures to the whole study group a negative predictive value of 95% is put forward as a more realistic figure. The results and the clinical pitfalls of the use of FNA cytology in diagnosing thyroid nodules are discussed. The authors conclude that FNA cytology is a reliable first diagnostic step in the diagnosis of thyroid nodules, even in a general hospital setting.