Validation of ultrasound-guided fine-needle aspiration in the diagnosis of thyroid cancer

Abstract

Introduction: fine needle aspiration has played an essential role in the evaluation of the patient with thyroid nodule, being a fast, minimally invasive method and the patient will quickly be reintegrated into his activities. Objective: to determine the validity of the Fine Needle Aspiration Puncture (FNAP) guided by ultrasound in the diagnosis of thyroid cancer in patients of the José Carrasco Arteaga Hospital in 2017. Methodology: validation study of diagnostic tests that compared fine needle aspiration puncture guided by ultrasound with histopathology (gold standard); 236 patients accomplished inclusion criteria. For the analysis, frequencies and percentages, standard deviation and mean were applied, according to quantitative and qualitative variables respectively; for the validation of the FNAP, tests of sensitivity, specificity, positive and negative predictive value were performed. The respective bioethical processes were applied. Results: 73.78% of patients were over 48 years old (mean of 56.52, SD +/- 13.51). According to the Bethesda classification, most patients presented atypia with 27.1%, followed by 26.3% of follicular neoplasia. By histopathology, 53.8% were benign with 43.2% of papillary carcinomas. The sensitivity was 73.39%; specificity 57.48%, validity index 64.83%; positive predictive value 59.7%; negative predictive value 71.57%; positive likelihood ratio 1.73, negative likelihood ratio 0.46; Youden index 0.31, Cohen's Kappa index 0.31. Conclusions:  The FNAP had a greater sensitivity than specificity; however, it could nCot be decisive at the time of diagnosis and decision-making.