Comparison of two different standards of care in detecting malignant thyroid nodules using thyroid fine-needle aspiration.

The aim of the present study was to verify the optimal method to obtain enough fine-needle aspiration (FNA) materials for detecting thyroid malignancy. A prospective study was performed by comparing two different regional standards of care. In one group a traditional FNA method mainly used in Asian countries, including China, was performed in which a single pass of a 22-G needle was applied with or without aspiration. In the other group, the method mainly used in Western countries was performed in which three passes of a 25-G needle with non-aspiration were undertaken for thyroid nodules. The study included 718 thyroid nodules from 695 patients. These nodules were allocated for three different methods of performing thyroid FNA. There were 332 thyroid nodules subjected to the traditional Asian FNA method using a 22-G needle with aspiration for 142 nodules and non-aspiration for 190 nodules. FNA using the Western method was performed with three passes of non-aspiration using 25 G for 386 nodules. All the FNAs were performed with the guidance of ultrasound. The components of the nodules were documented. All the samples were reported using the Bethesda System for Reporting Thyroid Cytopathology. Among the 22 G group, the non-diagnostic rate in the aspiration group was as high as 76.76%, which was significantly higher than 44.21% in the non-aspiration group (P<0.01). For the non-aspiration group, the non-diagnostic rate in the 25 G group was 34.97%, which was significantly lower than 44.21% in the 22 G group. In general, the non-diagnostic rate for the 25-G needle was 34.97%, which was significantly lower than 58.13% in all the 22 G groups. For the solid and mixed nodules, the non-diagnostic rate was lower in the 25-G needle group compared to the 22 G groups with statistical significance. The non-aspiration method using a 25-G needle with multiple passes can result in a higher diagnostic rate for thyroid FNA.