Although thyroid fine-needle aspiration (TFNA) is an excellent test in evaluating thyroid nodules, there are occasionally false negatives (FN). The clinical impact and pathologic features of FN TFNA is understudied in the peer-reviewed literature.
A cohort of patients with thyroid cancer was separated into those with referring FN TFNA and those with referring true positive (TP) TFNA. Preoperative characteristics, pathologic finding, and clinical outcomes were compared within the 2 groups.
A total of 192 patients with TP TFNA (n = 162) and FN TFNA (n = 30) were included in the study. There were no significant differences in the demographics or length of follow-up of the 2 groups. The FN TFNA group was more likely to have a larger clinical nodule size and experienced a significant delay from initial TFNA to surgery. The FN TFNA group was more likely to be diagnosed with the follicular variant of papillary thyroid cancer (73.3% vs 25.9%, P < .001), less likely to have positive lymph nodes at surgery (6.7% vs 35.8%, P = .001), and more likely to undergo 2-step surgery (30% vs 9.9%, P = .007). Despite the delay in diagnosis, persistent/recurrent or metastatic disease, incidence of aggressive histologic variants, and pT4 disease was not different in the 2 groups.
The clinical impact of FN TFNA at our high-volume center is minimal. Cancers in this setting are low grade, and outcomes are not adversely affected despite the delay in diagnosis.