CONICET | Buscador de Institutos y Recursos Humanos

Fine needle aspiration cytology (FNAC) is an important diagnostic tool for evaluating thyroid lesions. But, it has been reported that testing for BRAF p.V600E in residual thyroid FNA material provides helpful diagnostic information. In Argentina there are few data on the prevalence of BRAF p.V600E in our population. The aim of this study was 1) to evaluate the molecular test relative to the cytology study in FNA specimens, 2) to analyze the prevalence of the mutation of BRAF in patients with CPT in a population of Argentina, and 3) to evaluate the aggressive clinicopathological characteristics in relation to the BRAF mutation. A total of 106 FNA samples from thyroid nodules of patients (24 men and 82 women) were prospectively tested for BRAF mutation (realtimePCR/MCA assay). The analysis and correlation between the results of cytological evaluation, histological diagnosis, and molecular testing was performed. The cytological diagnoses were: 35% Bethesda II (n: 36), Bethesda III (n: 0), 22.3% Bethesda IV (n: 23), 2.9% Bethesda V (n: 3) and 36% Bethesda VI (n: 37). Only in 63 cases subsequent surgery was performed and the histological data were collected (40 PTC, 2 FTC, 4 follicular thyroid adenoma, 5 thyroiditis and 12 nodular hyperplasia). BRAF mutation was found in 29 patients (28 with Bethesda VI and 1 with cytology IV). The prevalence of BRAF mutation in PTC cytologies was 75.7%. The relative risk (RR) of the presence of lymph node metastases (N1) at diagnosis associated with the BRAF mutation was 6.74 (p0.05 for all). In conclusion, the BRAF molecular study in the residual material showed an acceptable diagnostic performance with a 75.7% of BRAF mutation prevalence in our population. The mutation was associated with the presence of lymph node metastases while othercharacteristics of aggressiveness showed no statistically significant difference.