Endocrinol Metab.  2020 Dec;35(4):696-715. 10.3803/EnM.2020.807.

Updates in the Pathologic Classification of Thyroid Neoplasms: A Review of the World Health Organization Classification

  • 1Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Pathology, Peking University Cancer Hospital & Institute, Beijing, China
  • 2Department of Pathology and Thyroid Disease Center, Izumi City General Hospital, Izumi, Japan
  • 3Department of Human Pathology, Wakayama Medical University, Graduate School of Medicine, Wakayama, Japan
  • 4Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea
  • 5Cancer Research Institute, College of Medicine, The Catholic University of Korea, Seoul, Korea


Advances in medical sciences and evidence-based medicine have led to momentous changes in classification and management of thyroid neoplasms. Much progress has been made toward avoiding overdiagnosis and overtreatment of thyroid cancers. The new 2017 World Health Organization (WHO) classification of thyroid neoplasms updated the diagnostic criteria and molecular and genetic characteristics reflecting the biology and behavior of the tumors, and newly introduced the category of borderline malignancy or uncertain malignant potential. Some neoplasms were subclassified, renamed, or redefined as a specific entity. This review introduces changes in the fourth edition WHO classification of thyroid tumors and updates the contemporary diagnosis and classification of thyroid tumors. We also discuss several challenges with the proposal of new diagnostic entities, since they have unique histopathologic and molecular features and clinical relevance.


Thyroid neoplasms; Classification; Diagnosis; Prognosis; Mutation; Clinical decision-making
Full Text Links
  • ENM
export Copy
  • Twitter
  • Facebook
Similar articles
Copyright © 2021 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr