Objective:

To evaluate the value of detection of

BRAF

V600E combined with cytodiagnosis in qualitative diagnosis of thyroid nodules (TNs) classified as Thyroid Imaging Reporting and Data System (TI-R

ADS) 4.

Methods:

The cytological and molecular biological results of 178 TNs classified as TI-RADS 4 that underwent ultrasound-guided fine-needle aspiration biopsy (US-FNAB) and detection of

BRAF

V600E during July 2019 and March 2020 were collected

and compared with the postoperative pathological results.

Results:

According to the Bethesda System for Reporting Thyroid Cytopathology

178 cases were divided into group A (accurate diagnosis) and group B (unclear diagnosis). In group A

the sensitivity

specificity

and accuracy of US-FNAB was 97.3%

88.9%

96.4%

respectively

and good agreement was observed (

=0.8220.071). The sensitivity

specificity

and accuracy of US-FNAB combined with

BRAF

V600E were 99.3%

88.9%

98.2%

and excellent agreement was observed (

=0.9040.055). We compared the diagnostic accuracy of US-FNAB and US-FNAB combined with

BRAF

V600E

and the difference was statistically significant (

2

=74.5

P

＜0.05). In group B

BRAF

V600E mutation occurred in 7 nodules

and all of them were papillary thyroid cancer (PTC).

Conclusion:

When the detection of

BRAF

V600E is added to US-FNAB

the accuracy rate would be improved by the combination of the two detection in nodules diagnosed correctly with cytological detection

and malignant nodules would be screened out in nodules diagnosed dimly with cytological detection. The combination of detection of

BRAF

V600E with US-FNAB comprehensively could improve the efficiency of qualitative diagnosis of TNs classified as TI-RADS 4.