Proceedings of the American Society of Cytopathology Companion Session at the 2019 United States and Canadian Academy of Pathology Meeting Part 1: towards an International System for Reporting Serous Fluid Cytopathology.

INTRODUCTION: The International System for the Reporting of Serous Fluid Cytopathology was initiated to provide a common language for cytopathology reports on body fluids.

MATERIALS AND METHODS: The International Academy of Cytology and the American Society of Cytopathology collaborated to provide evidence-based and expert-driven terminology for reporting serous fluids. Lead editors were selected and expert authors invited to form working groups for the diagnostic categories and special sections.

RESULTS: Preliminary results of the collaboration include the 6 diagnostic terminology categories: non-diagnostic, negative for malignancy, atypia of undetermined significance, suspicious for malignancy, malignant-primary, and malignant-metastatic. Four special sections on ancillary testing, peritoneal washings, cytotechnical aspects, and quality assurance will appear in the final text. Initial results of an international survey indicate strong support for a uniform terminology for reporting serous fluids.

CONCLUSIONS: This article outlines the initial findings of the collaboration as presented to the United States and Canadian Academy of Pathology at the 2019 annual meeting at the National Harbor, MD.