Comparison on the Use of Spinal (Stylet) Needle and Simple Needle in Ultrasound Guided Thyroid Nodule FNA; Does the Needle Affect Thyroid FNA Result?

Background: Thyroid fine needle aspiration (FNA) is currently the most acceptable method for evaluating thyroid nodules. Nonsatisfactory sample is the main limitation of FNA. It has been shown that spinal needles can reduce the number of non-diagnostic samples. Objectives: In this study, we decided to compare the results obtained using spinal (stylet) needle and simple needle in thyroid nodule FNA according to the agreement between them and with the pathology results as the gold standard. Patients and Methods: Sampling of thyroid nodules of 156 patients was performed by a simple non-stylet 23 gauge needle (A) and a spinal 22 gauge needle with stylet (B). The samples were provided to the pathologist for blind examination. All samples were obtained by an expert radiologist and the pathology examination was also performed by a pathologist expert in thyroid gland diseases. Blind analysis was done using SPSS Statistics for Windows, version 16 (SPSS Inc., Chicago, Ill., USA). Results: The results of FNA with needles A and B were reported unsatisfactory in 11.51 (18 subjects) and 3.84 (six subjects), respectively (P = 0.01). The result in 63.46% (99 subjects) of the participants, in whom FNA was obtained by needle B was introduced as a better sample by the pathologist in comparison with 36.44% (57 subjects) (P < 0.001). Cancer was diagnosed in 9.56 and 7.66 of the samples yielded by needles B and A, respectively, which was not statistically significant (P = 0.54). There was also a significant relationship between thyroid imaging reporting and data system (TI-RADS) score and FNA result. Conclusion: A significant relationship between the adequate sampling results, the qualitative examination result, TI-RADS score and the needle type indicates the importance of needle type on the results of thyroid FNA. Using spinal (stylet) needles may reduce the number of non-diagnostic samples in fine needle aspiration of thyroid nodules and therefore, can have a better effect on the results of this method.