The Diagnostic Value Of Ultrasound-guided Fine-needle Aspiration Biopsy In Different Size Of Suspect Thyroid Nodules

Objective: To investigate the adequacy of ultrasound-guided fine-needle aspiration biopsy(US-FNAB)cytology and compare the diagnostic value of US-FNAB cytology in different sizes of suspect thyroid nodules.Method: The patients with the US-FNAB cytology of suspect thyroid nodule in our hospital from August 2014 to December 2017 were reviewed.According to the Bethesda classification,the FNAB specimens of Bethesda I were defined as unsatisfied,the FNAB specimens of Bethesda ?~? were defined as satisfied.The nodules were divided into three groups by the maximum diameter: group 1: ?5mm;group 2: 5~10mm;group 3: >10mm,then calculated and compared the adequacy of US-FNAB cytology of each group.We screened out the cases with histopathology.Then we compared the concordance between the histopathology and the US-FNAB cytology,and compared the diagnostic value of US-FNAB cytology in three groups.Result:(1)There were 568 thyroid nodules with US-FNAB cytology,69 nodules with inadequate results,and 499 nodules with adequate results.The adequacy of US-FNAB cytology was 87.9%.The adequacy of US-FNAB cytology in group 1,2,3 was 77.8%,88.7%,90.0% respectively.The adequacy of US-FNAB cytology in group 1 was significantly less than group 2 and group 3(P<0.05).There was no significant difference in the adequacy of US-FNAB cytology between group 2 and 3(P>0.05).(2)There were 142 patients with 147 thyroid nodules who did the US-FNAB and operation.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of US-FNAB cytology were 69.6%,100.0%,74.1%,100.0%,36.4% in group 1,94.6%,87.5%,93.8%,98.1%,70.0% in group 2,96.1%,100.0%,96.4%,100.0%,71.4% in group 3.The sensitivity and accuracy of US-FNAB cytology in group 1 were significantly lower than that in group 2 and 3(P<0.05).There were no significant difference in three groups for the specificity,positive predictive value and negative predictive value(P>0.05).(3)The concordance between US-FNAB cytology and histopathology of the three groups was compared.There was a low concordance between US-FNAB cytology and histopathology in group 1(kappa value =0.404)while there were high concordances between US-FNAB cytology and histopathology in group 2 and 3(kappa value =0.742 and 0.841).Conclusion:(1)For thyroid nodules smaller than 5 mm,the inadequacy of US-FNAB cytology is higher,and the sensitivity and accuracy of US-FNAB diagnosis are lower.There is a low concordance between US-FNAB cytology and histopathology.So it is recommended to take positive follow-up for thyroid nodules smaller than 5 mm in order to reduce unnecessary puncture.(2)For thyroid nodules larger than 5 mm,the adequacy of US-FNAB cytology is higher,and the sensitivity and accuracy of US-FNAB diagnosis are higher.There is a high concordance between US-FNAB cytology and histopathology.So it is recommended for suspect thyroid nodules to endure US-FNAB.