A Comparison of Ultrasound-Guided Fine Needle Aspiration versus Core Needle Biopsy for Thyroid Nodules: Pain, Tolerability, and Complications.

Background: To compare pain, tolerability, and complications associated with fine needle aspiration (FNA) versus core needle biopsy (CNB). Methods: FNAs were performed using 23-gauge needles and CNBs were performed using 18-gauge double-action spring-activated needles in 100 patients for each procedure. Patients were asked to record a pain score using a 10-cm visual analog scale and procedure tolerability. Complications and number of biopsies were recorded. Results: The median pain scores were similar for the FNA and CNB approaches during and 20 minutes after the biopsy procedures (3.7 vs. 3.6, P=0.454; 0.9 vs. 1.1, P=0.296, respectively). The procedure was tolerable in all 100 FNA patients and in 97 CNB patients (P=0.246). The mean number of biopsies was fewer in the CNB group (1.4 vs. 1.2, P=0.002). By subgroup analysis (staff vs. non-staff), no significant difference was detected in any parameter. There were no major complications in either group, but three patients who underwent CNB had minor complications (P=0.246). Conclusion: FNA and CNB show no significant differences for diagnosing thyroid nodules in terms of pain, tolerability, or complications.