The value of a tiered cytology diagnostic reporting system in assessing the risk of malignancy in indeterminate serous effusions

Abstract

Background The International System for Reporting Serous Fluid Cytopathology was recently proposed as a tiered structure to provide consistent reporting terminology for serous effusions. Because of the variation in reporting practices for indeterminate serous effusions, namely, the atypia of undetermined significance (AUS) and suspicious for malignancy (SFM) groups, the authors retrospectively reviewed cases in these 2 categories at their institution and determined the associated risk of malignancy (ROM). Methods Pleural, peritoneal, and pericardial effusions that were reported as AUS or SFM over a 1‐year period were reviewed, and their associated ROMs were calculated based on confirmation of malignancy by previous and/or subsequent fluid and/or tissue biopsy specimens from the same general location. Results In total, 145 AUS and 98 SFM serous effusion cases were identified. The AUS category was used when the cells in question lacked the requisite quantitative (cell number) and/or qualitative (morphologic) features for a definitive diagnosis. Immunohistochemistry (IHC) or flow cytometry (FCM) was available in 15% of cases (n = 22) with inconclusive results. The ROM based on 69 cases with available follow‐up results was 39%. In contrast, the SFM category demonstrated cells that were morphologically suspicious for malignancy but sparse, precluding IHC or FCM (n = 63; 64%) or yielding inconclusive results (n = 35; 36%). The ROM in the SFM category, based on follow‐up results of 61 cases, was 64%. Conclusions The ROM for SFM was significantly higher than that for AUS (P < .01), supporting separate diagnostic categories for these 2 groups.

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

“…In the present study on pleural fluid samples, the calculated ROM for the categories AUS and SFM were 88.23% and 87.5%, respectively, similar to the high ROMs (AUS 71.8% and SFM 75.9%) calculated in the meta-analysis conducted by Farhani et al 8 (Table 4) In our study, The difference between the ROMs for the two categories was insignificant with the p-value of 0.78, which raises the dilemma regarding the exclusivity of these groups, is contrary to the findings by Hou et al 9 where they established that the two diagnostic categories are mutually independent groups. Moreover, the calculated ROM for the categories ND, AUS, and SFM are not significantly different from each other (Table 2), indicating that the criteria laid down for these groups must be reviewed, and more elaborative and strict criteria are laid down.…”

“…[1][2][3] The rationale behind this new system was derived from the already established reporting systems in cytology such as the Bethesda System (TBS) for Reporting Cervical Cytology, the Bethesda System for Reporting Thyroid Cytopathology (Bethesda Thyroid), the Paris System (TPS) for Reporting Urinary Cytology, and the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC). [4][5][6][7] This evidence-based and five-tiered system 8,9 targets the improvement of the communication between the clinicians and cytopathologists, consequently directing them to better patient management and therapeutic strategies. We present our experience with the recategorization of pleural fluid samples into the categories recommended by this classification system, highlighting the various challenges we encountered during the process.…”

Cytohistological Correlation in Pleural Effusions Based on the International System for Reporting Serous Fluid Cytopathology

“…No other diagnostic categories were evaluated in this publication. Sensitivity and specificity values were not calculated [ 22 ].…”

“…Several recent publications have looked at the risk of malignancy (ROM) for each of these categories. They have shown that values vary between affected cavities [ 5 , 6 , 17 , 18 , 19 , 20 , 21 , 22 ]. Most studies, however, were published before the development and implementation of TIS, with few exceptions [ 5 , 6 , 17 , 18 , 19 , 20 , 21 , 22 ].…”

A retrospective analysis of pleural effusion specimens based on the newly proposed International System for Reporting Serous Fluid Cytopathology

“…ROM was estimated according to the previously described methods 8,9,12 . Performance evaluation was conducted by measuring diagnostic accuracy, sensitivity, specificity, positive and negative predictive values for each pleural effusion sample 7,13 .…”