The international system for serous fluid cytopathology: Interobserver agreement

Abstract

Background: A number of categorization systems had been developed for the reporting of cytology specimens with the aim of providing uniform definitions, criteria, and diagnostic terminology. The intention of these systems is to improve reproducibility of diagnostic categorization with standardized estimates of malignancy risk. Required for the success of these systems is a high level of interobserver reproducibility for category assignment. Recently, the international system for serous fluid cytopathology (TIS) was proposed using the categories nondiagnostic, negative for malignancy, atypia of undetermined significance (AUS), suspicious for malignancy, and malignant. Little data exists documenting the interobserver agreement for these categories.Design: A search of the cytology records at the University of Missouri was performed for all pleural fluid specimens obtained between January 2014 and December 2019.A total of 200 specimens were reviewed independently by three board-certified cytopathologists. Specimens were characterized as nondiagnostic, negative, AUS, suspicious for malignancy, and malignant. Interobserver agreement was analyzed using Cohen's kappa.Results: Overall observer agreement was 68% and chance-corrected weighted agreement (weighted kappa) was 0.63. Agreement was good for categories negative and malignant, but poor for categories atypia of uncertain significance, and suspicious for malignancy. Conclusions:The TIS has performance characteristics similar to other cytologic classification schemes. Interobserver agreement is best for the negative (76%) and malignant (81%) categories. Interobserver agreement is poor for the category's AUS, and suspicious for malignancy. This is similar to interobserver agreement associated with other published categorization systems.

Digital Examination of LYmph node CYtopathology Using the Sydney system (DELYCYUS): An international, multi‐institutional study

“…It is conceivable that use of the Sydney system enhances interobserver agreement by providing a uniform terminology and clear criteria for classification. The rates of agreement observed are in line with those reported using other classification systems 21,25 …”

Risk of malignancy assessment of the International System for Reporting Serous Fluid Cytopathology: Experience in a community hospital setting and comparison with other studies

“…These heterogeneities might stem from a difference in served population-based characteristics, such as the prevalence of cancers, or different diagnostic concepts among institutions and individual pathologists even from the same country. [26][27][28] Furthermore, the follow-up approach to determining the ROM varied among different Jha 2021 15 Pergaris 2021 17 Xu 2021 11 Straccia 2022 12 Ahuja & Malviya 2022 16 Bharti 2022 9 Hou 2021 18b This was excluded from further pooled series because of a lack of data for some categories.…”

“…Our results indicated that there was significant heterogeneity in the frequency and ROM in data from different practices, especially for the ND, NFM, and AUS categories. These heterogeneities might stem from a difference in served population‐based characteristics, such as the prevalence of cancers, or different diagnostic concepts among institutions and individual pathologists even from the same country 26–28 . Furthermore, the follow‐up approach to determining the ROM varied among different studies.…”

Review of the impact of the International System for Serous Fluid Cytopathology

“…adenocarcinoma, lymphoma) are present. As a consequence, interobserver variation should decrease and the risk of malignancy (ROM) should be clarified 17 …”

“…As a consequence, interobserver variation should decrease and the risk of malignancy (ROM) should be clarified. 17 In the present review, we have assessed the global impact of the application of TIS, and we have summarised the reported data on the ROM for the five diagnostic categories.…”