FNA versus CNB in thyroid nodules, the experience at the Hospital Regional de Antofagasta

Abstract

Introduction: Fine-needle aspiration (FNA) plays an important role in the evaluation of patients with thyroid nodules, being a low-cost, fast and minimally invasive method. However, its high rate of inconclusive or insufficient results makes the core needle biopsy (CNB) technique an attractive alternative. Objective: The objective of this study is to evaluate the diagnostic accuracy of FNA versus CNB in thyroid lesions, comparing its results with the histopathological findings obtained in the surgical piece. Materials and methods: A retrospective analysis of the clinical registry of the Regional Hospital of Antofagasta was performed, analyzing the cases studied by FNA and CNB between January 2017 and December 2020. The study included 293 cases. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were determined. Results: The cytological and histopathological correlation showed a sensitivity for FNA of 67.9%, specificity of 88.9%, positive predictive value of 86.3%, negative predictive value of 72.7% and diagnostic accuracy of 78.2%. For CNB, sensitivity was 93.3%, specificity 100%, positive predictive value 100%, and negative predictive value 93.8%, with diagnostic accuracy of 96.6%. Conclusion: CNB is a sensitive and specific test that decreases the rate of non-diagnostic results. The results are comparable with those found in the literature.