Epidemiologic analysis of thyroid fine needle aspiration biopsies over a period of 18 years (1987-2004)

Introduction: Fine Needle Aspiration Biopsy (FNA) is a method widely used in the assessment of thyroid nodules. The main aim of this 18-year retrospective study was the investigation of the diagnostic value of FNA cytology in thyroid malignancy. Subjects and Methods: We retrospectively reviewed 1376 patients who underwent 1938 FNAs from 1987 to 2004 in the Department of Endocrinology, "Hippokration" General Hospital, Thessaloniki, Greece. Of them 178 subsequently underwent total or subtotal thyroid resection and a pathology report was available. Results: FNA cytology shows a sensitivity of 76.2% and a specificity of 90.5% for thyroid malignancy, with a significant agreement between FNA cytology and the histology following resection surgery (Cohen's method, p < 0.05). There was a considerable improvement in the diagnostic value of FNA cytology during the sub-period 1996-2004 as compared to the subperiod 1987-1995. Conclusions: 1) FNA is a reliable diagnostic method in the assessment of thyroid malignancy, 2) a non-diagnostic FNA should always be repeated, 3) meticulous follow-up is mandatory, even after a cytological result of benign hyperplasia and 4) increased experience can improve the diagnostic value of FNA in thyroid malignancy.