Predicting Malignancy in Thyroid Nodules with Benign Cytology Results: The Role of Conventional Ultrasound, Shear Wave Elastography and BRAF V600E

Background: Ultrasound-guided fine-needle aspiration (US-FNA) is the most accurate method for preoperative diagnosis of thyroid nodules, but how to deal with false negative results?

Objective: This study aimed to find preoperative diagnosis methods including Conventional Ultrasound (CUS), Shear Wave Elastography (SWE) and BRAF V600E testing to differentiate false negative nodules.

Methods: Forty-nine nodules in 49 patients with benign FNA results and pathological diagnoses were included. CUS and SWE features were evaluated. BRAF V600E analysis was performed after FNA. Diagnostic performances of three methods were analyzed in predicting malignancy in benign FNA results.

Results: Twenty-seven of 49 nodules were malignant, and 22 nodules were benign. Hypoechogenicity, taller-than-wider, irregular boundary, microcalcification, SWE max, SWE mean and BRAF V600E mutation were risk factors for malignancy. All 7 malignant nodules with BRAF V600E mutations and 18 of 20 malignant nodules without BRAF V600E mutations have two or more suspicious CUS features. Six of 7 malignant nodules with BRAF V600E mutations and 16 of 20 malignant nodules without BRAF V600E mutations had SWE mean value greater than the cut-off value.

Conclusions: CUS, SWE and BRAF V600E were diagnostic tools for malignancy in FNA benign nodules. Further clinical decisions should be considered for nodules with two or more suspicious CUS features and SWE parameters greater than cut-off values whether BRAF V600E is mutational or not.