Ten Key Questions on the 2023 Bethesda “AUS” Category: Practical Guidance for Surgeons, Endocrinologists, and Pathologists

The 2023 Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) redefines Atypia of Undetermined Significance (AUS) by introducing subclassification into AUS with nuclear atypia and AUS-other. This change reflects growing evidence that the risk of malignancy is subtype-dependent. For endocrine surgeons, this means that cytology can no longer be interpreted in isolation: AUS subtypes must be integrated with ultrasound patterns and, when appropriate, molecular data to guide individualized management.