WHO Reporting System for Lung Cytopathology (1st Edition)

―Establishment of international criteria for lung cytopathology―

Abstract

The role of respiratory cytology has changed rapidly with advances in technology and the advent of an era of cancer genome treatment. In response to these changes, the three-tiered classification of respiratory cytology that has been used since 1978 in Japan should be reviewed. New criteria were proposed by the joint working group. Furthermore, since 2020, the World Health Organization (WHO), the International Agency for Research on Cancer (IARC), and the International Academy of Cytology (IAC) have taken the lead in establishing an international respiratory reporting format named the WHO Reporting System for Lung Cytopathology. The WHO Reporting System for Lung Cytopathology was published at the end of 2022. The key points of this reporting system include : (1) consistency with the WHO tissue classification, (2) editing by a standing committee, an expert editorial board, editors, authors, and co-authors, (3) inclusion of key diagnostic features, risk of malignancy (ROM), ancillary tests, and other information, and (4) a list of the key diagnostic features, ROM, ancillary tests, and management recommendations for each diagnostic category. In the future, cytological diagnosis should be performed with the understanding that the purpose of the WHO Reporting System for Lung Cytopathology is for quality control and practical clinical application. In addition, cytology is expected to be further utilized for diagnosis and treatment of respiratory diseases by combining auxiliary tests such as immunocytochemical staining and molecular biological search using cytological specimens.