The previous edition ofThe Bethesda System for Reporting Thyroid Cytopathologyprovided important updates and advances in the practice of thyroid cytopathology. It was inspired by new developments in the field of thyroid cytopathology since the publication of the first edition in 2010. These included revised clinical guidelines for the management of patients with thyroid nodules, the introduction of molecular testing as an adjunct to cytopathologic examination, and the reclassification of the non-invasive follicular variant of papillary thyroid carcinoma as non-invasive follicular thyroid...