关键词: 甲状腺结节；Bethesda病理分级；超声检查；活组织检查, 细针

Abstract: Objective　To evaluate the value of ultrasound-guided thyroid fine needle aspiration （FNA） in the differential diagnosis of benign and malignant thyroid nodules，and to investigate the effect of nodule size on Bethesda classification.Methods　We retrospectively analyzed the clinical data of patients who underwent ultrasound-guided thyroid FNA of thyroid nodules in the Ningbo First Hospital in 2015 and 2016，as well as the pathological results according to the Bethesda reporting system.Histopathology was used as the gold standard to judge the value of thyroid FNA in differentiating benign from malignant nodules，and the effect of nodule size on Bethesda classification was also analyzed.Results　A total of 743 patients were included，and 755 nodules were analyzed.The nodule diameter was （10.4±7.1）mm.The FNA pathological results of 755 thyroid nodules were classified according to the Bethesda reporting system：there were 81（10.7%） nodules with unsatisfactory specimens，342（45.3%） benign nodules，80（10.6%） nodules with atypia of undetermined significance （AUS），3（0.4%） follicular neoplasms，91（12.1%） suspicious malignant nodules，and 158（20.9%） malignant nodules.The rate of satisfactory specimens was 89.3%（674/755）.There were no significant differences in the rates of unsatisfactory samples，AUS and malignant nodules between ≤10 mm and >10 mm nodules （P>0.05）.There were no significant differences in the rates of unsatisfactory samples and AUS between ≤5 mm nodules and >5 mm nodules （P>0.05）.The malignant rate was lower in ≤5 mm thyroid nodules than >5 mm nodules （P<0.001）.Among 202 nodules with surgical pathological results，FNA obtained consistent results in 173 nodules.The sensitivity，specificity，accuracy，positive predictive value，and negative predictive value of FNA in the diagnosis of thyroid nodules were 94.3%（150/159），85.7%（12/14），93.6%（162/173），98.7%（150/152），and 57.1%（12/21），respectively.Conclusion　Ultrasound-guided thyroid FNA has substantial value in differentiating benign and malignant thyroid nodules，with a very high positive predictive value；nodule size does not significantly affect Bethesda cytopathological classification，and the rate of satisfactory specimens is affected by the degree of proficiency.

Key words: Thyroid nodule；Bethesda system for reporting thyroid cytopathology；Ultrasonography；Biopsy, fine-needle