Fine-needle aspiration biopsy (FNAB) has become an established procedure for the basic examination of thyroid nodules, which remain common in our population. The widely used Bethesda system for reporting thyroid cytopathology has undoubtedly contributed to the understanding among clinicians and cytopathologists.
Since its publication in 2010, the system’s overall applicability has been tested by many studies and reclassification of follicular thyroid tumours has occurred. The consensus embedded in the latest version of the WHO classification was the impetus for a revision of the very successful Bethesda 2010 system in 2017.
We present a brief overview of the changes in the persistent categories of the original classification to the newly established format along with practical recommendations for routine FNAB diagnostics of thyroid lesions.