A quantitative analysis of thyroid fine needle aspiration (FNA) using needles with different gauges.

Objective: The aim of this study is to compare the results of three gauge (G) needles (22G, 23G and 25G) in terms of cell amount in thyroid fine needle aspiration (FNA).

Subjects and methods: In the retrospective study, a total of 443 patients undergoing FNA for the first time between 2017 and 2018 were included in the study, and assigned to 3 groups with 22-gauge, 23-gauge and 25-gauge needles, respectively.

Results: The cell amount of a suspicion for the four diagnosis groups, including malignancy and malignant, benign nodules, follicular of undetermined significance (FLUS), and follicular neoplasia was mainly in the range of 0-10000, 0-300, 0-150, and 500-2500, respectively. The cut-off values of 22G needle 20000, 300, 1000, and 2500, while the cut-off values of 23G and 25G were 10000, 400, 1000, and 2500; 5000, 400, 1500, and 2000, respectively for the four diagnosis groups.

Conclusion: Large-gauge needles resulted in more cellular specimens than small-gauge needles only in the cases of malignant tumors. Small-gauge needles resulted in a higher comfort level of the patients, and had no difference in cell number in nodules with abundant blood supply, compared with large-gauge needles.