Diagnostic adequacy of ultrasound-guided fine needle aspiration in thyroid nodules / 대한내과학회지

ABSTRACT

BACKGROUND: Fine needle aspiration (FNA) is regarded as initial diagnostic procedure for thyroid nodules due to its accuracy and safety. One of the limitations of FNA is variable rate of inadequate specimen. Recently, ultrasound guidance has been suggested as a valuable method to improve diagnostic performance of FNA. The aim of this study is to evaluate the rates of adequate specimen when FNA is done with ultrasound guidance. METHODS: This study was performed on 304 patients who underwent ultrasound-guided FNA for thyroid nodules. Ultrasound-guided FNA was performed due to various causes. RESULTS: Inadequate specimens were obtained from 62 patients (20.4%). The sizes of thyroid nodules from which specimen obtained were 1.63+/-1.17 cm for adequate specimen, 1.18+/-0.72 cm for inadequate specimen respectively and differed significantly (p=0.001). When patients were divided by the size of thyroid nodules, the rates of inadequate specimen were significantly different between the groups above 1.5 cm and less than 1.5 cm (p=0.04). The rates of inadequate specimen were also different according to the indications of ultrasound guidance, 25.4% in nonpalpable thyroid nodules and 11.4% in complex cysts. When complex cyst group was divided by the size of thyroid nodules, the rates of inadequate specimen were not different. CONCLUSION: There are less benefits of ultrasound-guided FNA for patients with nodule size less than 1.5 cm. We recommend ultrasound guidance for patients with complex cyst rather than nonpalpable thyroid nodules.