Comparison of cytological adequacy in ultrasound-guided fine-needle aspiration of thyroid nodules with different numbers of needle passes.

OBJECTIVE: The aim of this study was to compare the cytological adequacy rates of different needle passes in ultrasound-guided fine-needle aspiration biopsy of thyroid nodules and, thus, to help establish the criterion for selecting the number of needle passes according to the characteristics of thyroid nodules. PATIENTS AND METHODS: This single-center and randomized prospective study involved 207 consecutive patients with 240 solid or predominantly solid thyroid nodules. These nodules were randomly divided into a 1-pass group, a 2-pass group, and a 3-pass group. Then the nodules were sent for cytopathological diagnosis, and cytological results were classified according to the Bethesda classification. Bethesda I was defined as inadequate, and Bethesda Ⅱ-Ⅵ were defined as adequate. Then the cytological adequacy rates of different groups were compared. RESULTS: In total, 221 nodule specimens were considered as adequate and 19 nodule specimens inadequate. The overall adequacy rate was 92.1%. However, there were no significant differences among the 1, 2, and 3-pass groups in terms of adequacy rates (91.3%, 92.5%, and 92.5%, respectively). CONCLUSIONS: The number of needle passes does not significantly affect the cytological adequacy in ultrasound-guided fine-needle aspiration of solid or predominantly solid thyroid nodules. The cytological adequacy of one-needle pass is comparable to those of two and three-needle passes.