Is There a Role for On-Site Evaluation of Thyroid Fine Needle Aspiration to Reduce the Nondiagnostic Rate?

The use of immediate on-site evaluation of fine-needle aspiration biopsy (FNAB) specimens can determine the adequacy of specimens and provides a specific preliminary diagnosis. In this prospective study, we evaluated the impact of on-site assessment of thyroid FNAB performed under ultrasound guidance. Totally, 204 (170 female, 34 male) patients (102 on site, 102 control group) were included. The patients were randomized on site and regular cytologic examination groups. Quick May-Grünwald Giemsa stain was used for on-site examination and FNA was continued until adequate aspirate for optimal cytological examination. Two (2.0 %) of the 102 patients evaluated with on-site examination had a nondiagnostic result. However, 16 (15.7 %) of the 102 patients examined by regular cytologic examination method, had nondiagnostic result. The difference between these two groups was statistically significant (p < 0.0001). The major cause of a nondiagnostic thyroid FNAB specimen is the failure to aspirate a sufficient number of cells necessary for diagnosis cystic lesions. Immediate on-site evaluation can significantly decrease the nondiagnostic rate of thyroid FNAB specimens.