Application of the International System for Reporting Serous Fluid Cytopathology in routine reporting of pleural effusion and assessment of the risk of malignancy

Abstract

Introduction:The International System for Reporting Serous Fluid Cytopathology (ISRSFC) was proposed by the International Academy of Cytology and the American Society of Cytopathology.Aim of the study: We have applied this system for reporting of pleural effusion cytology and report our experience.Materials and Methods: All the pleural effusions from January 2019 to June 2020 were retrieved from the database. All these cases were reviewed and recategorized according to the proposed system of 5 categories: non-diagnostic (ND), negative for malignancy (NFM), atypia of uncertain significance (AUS), suspicious for malignancy (SFM), and malignant (MAL). The risk of malignancy (ROM) for each category was evaluated.Results: A total of 939 cases were studied. The age of patients ranged from 2 to 88 years, and the volume of fluid ranged from 1 to 600 ml. There were 41 ND (4.37%), 697 NFM (74.23%), 44 AUS (4.69%), 27 SFM (2.88%), and 130 MAL (13.84%) cases. The ROM for the categories were found to be 87.5%, 51.61%, 88.23%, 87.5%, and 100% respectively. Conclusions:The ISRSFC is a user-friendly system for use in reporting of pleural fluid.The criteria for defining the various categories need to be further elaborative and stricter for this system to be more effective. More studies are required for the estimation of the ROM for each category.

Application of the International System for Reporting Serous Fluid Cytopathology with Cytohistological Correlation and Risk of Malignancy Assessment

“…Pericardial effusions only included three cases, and their distribution was 33.33% (one case) NFM and 66.67% (two cases) MAL. Our results are compatible with those of other studies [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ], some of which include only pleural effusions [ 25 , 26 , 27 , 30 ], while others include pleural and peritoneal effusions [ 24 , 28 , 31 , 32 ], and one includes only pericardial effusions [ 29 ]. In regard to pleural effusions, the rate of malignancy reported from oncologic centers is significantly higher [ 31 ], while a similar rate to ours is reported from other institutions [ 26 ], probably related to the “general” nature of our institution.…”

“…Meanwhile, for peritoneal effusions, the corresponding values were 80%, 99.3%, 98.5% and 89.6%. The accuracy parameter values are in line with those reported in other studies [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Notably, oncologic centers report lower sensitivity [ 25 , 31 ].…”

“…The most common malignancy in pleural effusions was secondary to breast cancer, followed by lung cancer and lymphoma. A similar order of secondary malignancy origin has been reported by other studies [ 25 , 26 , 30 , 31 ]. A well-developed hematologic clinic in our hospital accounts for the relatively high incidence of lymphomas and leukemias in our series, which, surprisingly, was much higher before the COVID-19 era.…”

“…A comprehensive review by Farahani and Baloch [ 24 ] reported mean ROM for all types of serous effusions of 17.4%, 20.7%, 65.9%, 81.8% and 98.9% for the abovementioned TIS categories. Other studies have reported mean ROM ranging between 40% and 87.5% for ND, 20.16% and 51.61% for NFM, 39% and 88.23% for AUS, 64% and 87.5% for SFM and 100% for MAL [ 25 , 26 , 28 , 31 ]. Our results are more compatible with the ROM reported by Kundu et al and Xu et al, namely 20% and 26.7% ND, 12% and 16.7% NFM, 50% and 62.3% AUS, 77.8% and 94.4% SFM and, finally, 100% for MAL [ 30 , 32 ].…”

The international system for serous fluid cytopathology: Interobserver agreement

“…Early reports utilizing the system have suggested that it is user friendly, but criteria defining various categories should be further extended and better defined for the system to be more effective. 1 In an effort to define interobserver reproducibility for the TIS, we conducted a study of interobserver agreement using the definitions and criterial published in the TIS monograph. 2 Each of the cytopathologists reviewed the TIS monograph before commencing specimen review.…”