The Adequacy of Ultrasound-Guided Fine Needle Aspiration in Thyroid Nodules / 대한내분비학회지

ABSTRACT

BACKGROUND: Fine needle aspiration(FNA) is an accurate and safe method for the diagnosis of thyroid nodules. One of the limitations of FNA is the variable rate of unsatisfactory specimens, especially in small sized, deep seated or complex cystic nodules. To overcome this problem, ultrasound-guided FNA(US-FNA) has been widely used. In this study, the adequacy of cytologic specimens by US-FNA was compared with that of conventional palpation-guided FNA(P-FNA). METHODS: The medical records of all patients who were engaged in FNA due to thyroid nodules at Chungnam National University Hospital from January 2003 to July 2004 were retrospectively examined. The US-FNA and P-FNA were performed in 114 and 185 patients, respectively. RESULTS: Comparison of the adequacy of the two techniques in providing sufficient material for the cytologic diagnosis showed that specimens in 24(13.0%) and 6(5.3%) patients collected by P-FNA and US-FNA, respectively, were unsatisfactory(P=0.031). A total of 23 patients underwent thyroid surgery due to strong suspicion of malignancy at cytologic finding and/or on clinical judgement. Seventeen patients belonged to the P-FNA group and 6 patients to the US-FNA group. In the P-FNA group, a histologic diagnosis revealed two false-negative cytologic findings, but no false-negative findings were found in the US-FNA group. CONCLUSION: Compared with P-FNA, US-FNA may reduce the possibility of unsatisfactory cytologic specimens and the rate of false-negative diagnosis, and may improve the diagnostic accuracy in investigating thyroid nodules