The Diagnostic Value And Clinical Significance Of FNAC Combined With BRAF^V600E Mutation Detection In Hashimoto’s Thyroiditis Combined With Papillary Thyroid Carcinoma

Objective:To analyze the difference in the diagnostic efficacy of preoperative fine-needle aspiration cytology combined with BRAF^V600E mutation detection compared with fine-needle aspiration cytology alone in the diagnosis of benign and malignant thyroid nodules combined with Hashimoto’s thyroiditis,and to investigate the combined effect of HT and BRAF^V600E mutations on the clinical and pathological features of PTC.Methods:Patients with thyroid nodules who underwent fine needle aspiration cytology in outpatient clinics were selected,and BRAF^V600E mutation detection was performed at the same time.222 patients who finally received surgical treatment were included in the study.The patients’FNA results,BRAF mutation detection results,postoperative paraffin pathological results,whether combined with HT and clinical data（including age,gender,thyroid function,and related antibody status,tumor size,multifocal,and lymph node metastasis）were collected.（1）Taking postoperative pathological results as the gold standard,the sensitivity,specificity and accuracy of preoperative FNAC alone and FNAC combined with BRAF^V600E mutation detection in the diagnosis of PTC combined with HT were compared;（2）The BRAF^V600Emutation rate in PTC with HT and without HT was compared;（3）to analyze the effect of HT on clinicopathological features and thyroid function of PTC patients;（4）to analyze the effect of BRAF^V600Emutation on clinicopathological features and thyroid function of PTC patients;（5）to analyze the comprehensive effects of HT and BRAF mutations on clinicopathological features of PTC patients;（6）to analyze the risk factors of central lymph node metastasis in PTC patients.Results:Of 2227patients,14 had nodular goiter and 213 had PTC.Among the PTC patients,111 patients（52.1%）were combined with HT,and 135 patients（63.4%）had BRAF mutations.（1）The BRAF^V600E mutation rate of PTC patients with HT was lower than that of PTC without HT patients（54.1%vs 73.5%）;（2）For PTC patients with HT,the sensitivity of FNAC diagnosis was 93.69%,the specificity was 90.90%,The accuracy is 93.44%.The sensitivity,specificity and accuracy of FNA combined with BRAF^V600E mutation detection were 97.30%,90.90%and 96.72%,respectively.Combined detection can improve the sensitivity and accuracy of diagnosis（p<0.05）;（3）PTC patients with HT were more female than those without HT（83.8%vs 63.7%）（p<0.05）.Fewer lymph node metastases in the central group,but the difference was not statistically significant.In addition,compared with PTC patients without HT,T3 and T4 tended to decrease in PTC patients with HT,while TPOAb and TGAb tended to increase（p<0.05）;（4）Compared with PTC patients with BRAF wild type,patients with BRAF^V600E mutation had larger tumor diameter,and more central LN metastasis（51.9%vs 21.8%）（p<0.05）;（5）Compared with HT（+）BRAF（-）patients,HT（+）BRAF（+）patients had larger tumor diameters and had a higher rate of central LN metastasis.Compared with the HT（-）BRAF（+）group,the proportion of women in the HT（+）BRAF（+）group was higher.The central LN metastasis rate was lower in the HT（+）BRAF（-）group than in the HT（-）BRAF（-）group.Compared with the HT（+）BRAF（-）group,the mean age of the patients in the HT（-）BRAF（+）group was younger,there were more male patients,the tumor was more aggressive,and the proportion of lesions with a diameter of≧1cm was higher.The central LN metastasis rate was also higher;（6）tumor size（≧1cm）and BRAF^V600E mutation were independent risk factors for central LN metastasis in PTC patients.Conclusions:（1）FNAC combined with BRAF^V600E mutation detection can improve the sensitivity and accuracy of PTC combined with diagnosis;（2）BRAF^V600E mutation increases the aggressiveness of PTC,Even with HT,BRAF^V600Emutated PTCs have higher aggressiveness;（3）HT can reduce the probability of central LN metastasis for BRAF-wild-type PTCs,but due to the promoting effect of BRAF^V600E mutations on the aggressiveness of PTCs,HT cannot play a protective role in central LN metastasis;（4）larger tumor diameter（≧1cm）and BRAF^V600E mutation are independent risk factors for central LN metastasis in PTC patients.