Endocrine Abstracts

JOINT2144

Introduction: Fine needle aspiration puncture (FNA) is the method of choice for the study of the thyroid nodule. However, its diagnostic yield decreases in case of indeterminate cytological results. Our aim was to evaluate the usefulness of molecular study of the BRAF gene in thyroid nodule aspirate samples in deciding the therapeutic attitude.

Material and Methods: Retrospective observational study of 51 patients evaluated at the Thyroid Nodule consultation of the Hospital Universitario Clínico San Cecilio who underwent FNA and BRAF gene sequencing on thyroid nodule between October 2019 and February 2024.

Results: Thirty-five females and 16 males were studied. The mean age of the sample was 52.8 ± 12.5 years. The cytological results of FNA of the thyroid nodule according to the Bethesda system were: 66.7% BIII, 11.8% BV, 9.8% BIV and 3.9% BII, 7.9% BI. BRAF V600E mutation was present in 17.6% of the sample. 29 patients had undergone surgery and 18 of them had papillary thyroid carcinoma on pathology. In the intervened patients, total thyroidectomy was more frequent than haemithyroidectomy in those patients with mutated BRAF gene (P = 0.001) and pathological anatomy of malignancy more frequent in those with BRAF gene mutation (P=0.026). In patients with Bethesda III and BRAF gene mutation, the decision to perform total thyroidectomy compared to haemithyroidectomy was more frequent (P=0.006) as well as an anatomopathological diagnosis of papillary thyroid carcinoma of the surgical specimen compared to benignity (P = 0.055).

Conclusions: The study of mutations in the BRAF gene is useful for the therapeutic decision of thyroid nodules with indeterminate cytological results, as well as to determine the extent of thyroid surgery.