Repeated fine-needle aspiration of the thyroid in benign nodular thyroid disease: critical evaluation of long-term follow-up.

Fine-needle aspiration (FNA) is the most effective diagnostic means in the management of nodular thyroid disease. Therefore, we decided to evaluate the diagnostic reproducibility of FNA and the usefulness of repeated FNA in benign nodular thyroid disease. We evaluated 799 satisfactory aspirations performed in 306 patients (298 females) aged 14–84 years, followed for 2–12 years. FNAs were performed on an annual basis. Of all patients, 299 (97.71%) maintained benignity: 230 (75.16%) repeated the same cytologic pattern, and 69 (22.54%) showed diagnostic variations within benign pathologies. In 3 patients (0.98%) the diagnosis changed to suspicious and in 4 (1.30%) to papillary carcinoma in the whole group. Of these 4 cases, 1 was diagnosed in the second (0.57%) and 3 in the third repeat FNA (2.25%). In 6 cases in which increased nodular size was observed, no change to malignancy was detected, while 3 of the carcinomas found showed no changes in size. In conclusion: (1) The variation in cytologic diagnoses wi...