Significance Of FNAC,BRAF Mutations And Intraoperative Frozen Section In Surgical Decision Of Thyroid

Objective: To evaluate the diagnostic value of preoperative fine needle aspiration cytology(FNAC)of thyroid nodules,BRAF mutation status and intraoperative frozen section(FS)evaluation.By assessing the correlation between BRAF mutation and clinic-pathological features to optimize surgical decision-making and treatment strategy.Materials and Methods: This study was conducted by retrospectively analysis of clinical pathologic factors,cytology results,and BRAF mutation status in 346 patients with 358 punctures in fine-needle aspiration biopsies of thyroid nodules,in the period of October 2016 to February 2018.FNAC results were classified using the Bethesda Thyroid Cell Pathology Reporting System(BSRTC).The BRAF mutation was detected using the Amplified Block Mutation System(ARMS),and the intraoperative FSs were evaluated according to the histopathological diagnosis.The sensitivities and specificities of FNAC results,BRAF mutation status,FS analysis alone or their combinations were compared.Results: 322 out of 346 patients(93%)were pathological diagnosis of thyroid papillary carcinoma;333 out of 358 punctures(93%)were malignant nodules.The sensitivity and specificity of BSRTC VI was the high-est(75.7% and 76%)according to The Receiver Operating Characteristic(ROC)analysis of FNAC.The BRAF mutation analysis significantly increased the efficiency,with 89.5% sensitivity,and 84% specificity,compared to BSRTC.Furthermore,the diagnostic efficacy is significantly higher in FS(with 96.1% sensitivity and 95.8% specificity)compared to BSRTC or BRAF mutation analysis alone(with 95.5% sensitivity and 64% specificity),and the combination of both(with 69.7% sensitivity and 96% specificity).By combination of these methods,the diagnostic performance can be improved to varying degrees.The preoperative FNAB detected BRAF mutation was not associated with adverse pathological features including capsule infiltration,neurovascular infiltration,monohepatic carcinoma,multifocal,lymph node metastasis,and clinical stage.Conclusions:(1)The diagnostic performance of BRAF mutation analysis is better than BSRTC classified FNAC;(2)The combination of both methods can improve diagnostic sensitivity and specificity.Patients with both positive score should be recommended for surgery,and with both negative should follow with dynamic monitoring.The surgical strategy should be combined with comprehensive intraoperative FS assessment;(3)The larger the diameter of thyroid puncture nodules,the more favorable for cytological diagnosis;(4)Detection of preoperative BRAF mutation contributes to cytological classification;(5)Since BRAF mutations are not relative to adverse pathological features,its significance of guiding surgical decision remains to be further studied.