Screw needle cytology of thyroid nodules is associated with a lower nondiagnostic rate compared to fine needle aspiration

Abstract

Background: Fine needle aspiration (FNA) cytology is the method of choice to exclude malignancy in thyroid nodules. A major limitation of thyroid FNA is the relatively high rate (13-17%) of non-diagnostic samples. The aim of this study is to determine the diagnostic yield of a screw needle compared to the conventional FNA. Methods: We retrospectively analysed thyroid nodule cytology of all patients that underwent thyroid nodule fine needle or screw needle aspiration between July 2007 and July 2012 in a single academic medical centre. Cytology results were categorized according to the Bethesda classification system. Results: In total, 644 punctures of thyroid nodules from 459 patients were available for analysis. The screw needle was used 531 times, and the conventional fine needle 113 times. The percentage of non-diagnostic cytology was significantly lower in the screw needle samples than in the fine needle samples (3% vs 17%, P<0.001). Conclusion: This study shows a significantly better diagnostic performance of the screw needle compared to the conventional fine needle in cytology of thyroid nodules.