The previous edition of The Bethesda System for Reporting Thyroid Cytopathology provided 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 neoplasm with papillary-like nuclear features (NIFTP).

This new third edition provides updates to the current reporting terminology and diagnostic criteria, including new information on ancillary molecular testing, as well as imaging findings and clinical management. This book provides a more unified approach to diagnosing and reporting thyroid FNA interpretations. It simplifies the reporting structure by settling on just one name for each of the six categories and aligning terminology with the most recent classification of thyroid tumors by the World Health Organization.

Written by experts in the field, The Bethesda System for Reporting Thyroid Cytopathology, Third Edition aims to inspire advances in thyroid cytopathologic diagnosis and the betterment of patients with thyroid nodular disease. It serves as a reference guide not just for pathologists, but also endocrinologists, surgeons, and radiologists.

This atlas is the offspring of the "The National Cancer Institute (NCI) Thyroid Fine Needle Aspiration (FNA) State of the Science Conference," hosted by the NCI and organized by Dr. Andrea Abati. Preparations for the conference began 18 months earlier with the designation of a steering committee and the establishment of a dedicated, p- manent web site. The meeting took place on October 22 and 23, 2007 in Bethesda, Maryland and was co-moderated by Susan J. Mandel and Edmund S. Cibas. The discussions and conclusions regarding terminology and morphologic criteria 1, 2 from the meeting were summarized in publications by Baloch et al. and form the framework for this atlas. The atlas is organized by the general categories of "Nondiagnostic," "Benign," "Follicular Neoplasm/Suspicious for a Follicular Neoplasm", "Suspicious for Malignancy," and "Malignant," and it includes the defi- tions and morphologic criteria of these categories as set forth by Baloch et al. The majority of the conference participants also agreed on a category of "undetermined significance," which is incorporated in this atlas (Chap. 4). It is critical that the cytopathologist communicate thyroid FNA interpretations to the referring physician in terms that are succinct, unambiguous, and helpful clinically. We recognize that the terminology used here is a flexible framework that can be modified by individual laboratories to meet the needs of their providers and the patients they serve.