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Updated: Nov 30, 2025

Detection of Extravascular Trypanosoma Parasites by Fine Needle Aspiration
Published on: August 7, 2019
Comparison of core-needle biopsy and repeat fine-needle aspiration for thyroid nodules with inconclusive initial
Seon Min Jung1, Hye Ryoung Koo2, Ki Seok Jang3
1Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea.
Purpose:
We aimed to compare the efficacy of ultrasound-guided core-needle biopsy (CNB) with repeat fine-needle aspiration (rFNA) cytology in thyroid nodules with inconclusive results in initial fine-needle aspiration cytology.
Methods:
We studied 402 patients who required a repeat biopsy of thyroid nodules using ultrasound-guided CNB (n = 192) or rFNA (n = 210) because of inconclusive results in initial FNA, corresponding to categories I, III, and IV of the Bethesda System for Reporting Thyroid Cytopathology. If repeat biopsy results were benign (category II), suspicious malignancy (category V), or malignancy (category VI), they were defined as "diagnostic results". The diagnostic yield and performances of repeat biopsy were analyzed and compared between the rFNA and CNB groups.
Results:
The diagnostic results were obtained significantly higher in the CNB group than in the rFNA group (72.4% vs. 52.4%; P < 0.001). In the subgroup analysis, the diagnostic results were significantly higher in the CNB group than in the rFNA group for patients of categories I and III (P < 0.001 in both) in initial FNA. However, in patients with category IV nodules, there were no significant differences in diagnostic results between the two groups (P = 0.46).
Conclusion:
Compared to rFNA, ultrasound-guided CNB is useful and effective as a repeat biopsy option for thyroid nodules with non-diagnostic results (category I) and atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS) (category III) in initial FNA.

