Comparison of Ultrasound Findings and Fine Needle Aspiration Results Between Anti-Thyroid Peroxidase Positive and Negative Patients with Nodular Goiters

Introduction: Ultrasonography is an optimal approach for thyroid gland evaluation, nodule detection and cancer risk assessment in patients with thyroid nodules. Almost all patients with Hashimoto’s thyroiditis have high levels anti-thyroid peroxidase (anti-TPO) antibodies. Objectives: This study aimed to evaluate the relationship between ultrasonography and fine needle aspiration (FNA) results in anti-TPO antibodies positive and negative patients with nodular goiters. Patients and Methods: This cross-sectional study included 128 patients with nodular goiters, referred to endocrinology clinic of imam Reza hospital, Tabriz, Iran. Anti-TPO levels above and below 16 IU/mL were considered as positive and negative, respectively. All patients underwent thyroid ultrasonography, and eligible nodules were subjected to FNA. Results: Of 128 patients, 33.6% and 66.4% were anti-TPO positive and negative, respectively. FNA was conducted on 196 nodules. A significant relationship was observed between sonographic and FNA results in low and intermediate-suspicion nodules. Chronic lymphocytic thyroiditis (CLT) was more frequently reported in low-suspicion nodules of the anti-TPO positive group (P≤0.0001). In addition, in intermediate-suspicion nodules, CLT was reported in 33.3% of patients in the anti-TPO positive group (P=0.026). No significant difference was observed between other nodules. Conclusion: Based on our findings, when a nodule is classified in low or intermediate-suspicion categories, the possibility of CLT following FNA is significantly higher in the anti-TPO positive group, compared to the anti-TPO negative group.