Pre-Operative Cytological Evaluation of Thyroid Nodules According to the 2017 Bethesda System

Objective: This study aims to present the experience of the implementation of the Bethesda system for reporting thyroid cytopathology in Alpha Prolipsis Medical Laboratories, a private medical laboratory located in Athens, Greece. Methods: 617 FNAs, performed since 2017, were included in the study. Reports were issued according to The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). Aspirates were prepared with both conventional and liquid based cytology methods and were evaluated by two board certified cytopathologists. Diagnostic reproducibility and accuracy were evaluated. In 106 of these cases the cytological diagnosis was histologically confirmed. Results: Out of the 533 cases cytologically diagnosed as benign, 7 false negative results were obtained by FNA, whereas out of the 37 cytological diagnoses of probably or definitively malignant tumors one case was found histologically to be follicular adenoma. In this trial, the diagnostic accuracy of FNA was 96.7%, the specificity 94% and the sensitivity 87%. Conclusions: Our results show that FNA is a valuable examination technique in the preoperative evaluation of thyroid nodules. The integration of the 2017 Bethesda System for Reporting Thyroid Cytopathology is effective with an overall accuracy around 92%.