Sex variability of fine-needle aspiration reliability in the diagnosis of malignancy in thyroid nodules ≥4 cm

BackgroundThe effect of sex on fine-needle aspiration (FNA) diagnosis of thyroid cancer remains unknown. This study determines the reliability of FNA when evaluating thyroid nodules ≥4 cm in women and men.MethodsProspectively collected data of 1,068 patients who underwent FNA and thyroidectomy at a tertiary medical center were retrospectively reviewed. Data were stratified by sex and thyroid nodule size ≥4 cm.ResultsThe FNA false-negative rate for thyroid malignancy in women and men was 17% and 0%, respectively. FNA was less predictive of malignancy in women (odd ratio = 31.7; 95% confidence interval, 19.2 to 52.5; P < .0001) compared with men (odds ratio = 51.7; 95% confidence interval, 11.8 to 225.1; P < .0001) with thyroid nodules ≥4 cm.ConclusionsFor the diagnosis of malignancy in large thyroid nodules, FNA may be less reliable in women compared with men. This study advocates using a more aggressive approach that includes surgical resection for definitive diagnosis in women with thyroid nodules ≥4 cm.