Cytodiagnosis of pleural effusions according to The International System for Reporting Serous Fluid Cytopathology: retrospective analysis of oncological dispensary experience

Abstract

BACKGROUND. The International Serous Fluid Cytopathology Reporting System (TISRSFC) was proposed in 2020 to standardize cytological reports and include information on perceived risk of malignancy in reports. It is necessary to analyze the use of TISRSFC to determine the principles of rational practical implementation and possible improvement of this classification. AIMS: to assess the possibility and results of the application of TISRSFC (2020) in the cytodiagnosis of pleural effusions in the organizational technologies and resource provision of a regional oncological dispensary. MATERIALS AND METHODS. An observational, crossover, retrospective, crossover study. A comparative analysis of cytological analyzes of pleural effusion with clinical and anamnestic information, histological, immunohistochemical results of 1507 patients. The microscope slide were prepared by the traditional smear method, as well as by liquid cytology. preparations were stained by Papanicolaou and Pappenheim methods. The immunocytochemical tests were performed if necessary. RESULTS: The following cytological reports corresponding to the TISRSFC categories were formulated: non-diagnostic material (C I) - 11 (0.7%), absence of malignant tumor cells (C II) - 946 (62.8%), atypia of unknown significance (C III) - 61 (4.0%), suspicion of a malignant process (C IV) - 13 (0.9%), malignant process (C V) - 476 (31.6%). There were 37 (7.8%) cases of the primary tumor - mesothelioma, 398 (83.6%) cases of metastatic tumors, including 41 (8.6%) cases of non-epithelial tumors in category C V. Immunocytochemical tests of pleural fluid were performed in 273 (18.1%) cases. Risk of malignancy (ROM) was 9.1% (1/11) for C I; 1.2% (11/946) for C II; 59.0% (36/61) for C III; 84.6% (11/13) for C IV and 100% (476/476) for C V. Cytodiagnosis with immunocytochemistry in unclear cases is characterized by a sensitivity of 92.5%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 88.5%, and an accuracy of 96.6%.