Background/aim: Fine-needle aspiration biopsy is an established method for the evaluation of thyroid nodules, but it has not been standardized worldwide yet. Adequacy of the aspirations is affected by several factors. The aim of this study is to determine the main factors affecting the adequacy and to suggest a procedural technique expected to reduce repeated procedures.
Materials and methods: A total of 393 aspiration procedures performed using either 22-gauge or 27-gauge needles were included in the study. The samplings were classified as inadequate or adequate according to the cytopathological reports, and results were compared.
Results: The rate of adequate samplings was higher in the 27-gauge group and the difference was statistically significant. Neither the size of nodules nor the number of slides used for smearing affected the adequacy. There was not a statistically significant relation between the needle size and the nodule size or the number of slides in terms of adequacy.
Conclusion: Needle size is an important factor that affects the adequacy of samplings. The nodule size and the number of slides do not affect the adequacy. However, bloody and thicker smears are difficult for pathologists to evaluate and result in inadequacy.