Fine-Needle Aspiration of the Thyroid Gland: The 2017 Bethesda System

Abstract Fine-needle aspiration (FNA) is an essential test in the evaluation of a patient with a thyroid nodule. The result of the FNA determines, in large part, whether a patient can be followed clinically or referred for surgery. Guidelines have been established for selecting a nodule for aspiration. The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has standardized the reporting of thyroid cytopathology and consists of the following six diagnostic categories: nondiagnostic, benign, atypia of undetermined significance/ follicular lesion of undetermined significance (AUS/FLUS), follicular neoplasm, suspicious for malignancy, and malignant.