Comparison of 21 Gauge vs 25 Gauge Needles in US Guided Fine-Needle Aspiration Cytology of Thyroid Nodules

Abstract Background Thyroid nodules are frequent among the general population. Ultrasound is the most commonly used imaging technique in the evaluation of thyroid nodules, Fine needle cytology (FNC) has been routinely used as the baseline investigation for diagnosis of nodular thyroid disease. Its advantages include minimal invasion and high sensitivity, specificity, and accuracy. Objective Our aim is to compare the sample adequacy of FNA sample obtained by 21 gauge needle versus 25 gauge needle, aiming to improve the overall quality of FNC and hence better evaluation of thyroid nodules avoiding repeating FNC and unnecessary thyroidectomies. Patients and Methods Our study was conducted on 22 adult patients with thyroid nodules, whose ages range between 17 and 68 years old and were referred to undergo FNA procedures. Results 22 patients with thyroid nodules were included in this study, the mean of Mayers score was 4.23 ± 2.18 and ranged from 1 to 8, while most of patients were adequate by (72.73%). Regarding the difference between two groups in Mayers score & adequacy, there was no statistically significant difference between the two groups in Mayers score nor adequacy (as P-value >0.05). Conclusion In conclusion concerning the diagnostic accuracy either 21- or 25-gauge needles can be used. We recommend using 21 gauge needles for markedly calcified nodules, because 25-gauge needles bend more easily in such cases.