Application of the international system for reporting serous fluid cytopathology on reporting various body fluids; experience of a tertiary care hospital

Abstract

Objectives: Cytological examination of effusion sample is a preliminary and minimally invasive method for the diagnosis of body fluids. Recently, the International System For Reporting Serous Fluid Cytopathology (ISRSFC) and the Indian Academy of Cytologist (IAC) have published guidelines for reporting effusion cytology and calculating the risks of malignancy (ROMs) for each defined category. We report our 2 years of experience in reclassifying and assessing the feasibility of applying ISRFSC and IAC categories to effusion fluid and to provide an estimate of the risk of malignancy for each diagnostic category. Material and Methods: Cytological reports of patients from January 2019 to December 2020 were retrieved and reclassified into a five-tiered classification scheme as per ISRSFC guidelines. Cellblock and immunohistochemistry were performed in selected cases. Clinico radiological and histopathological information were obtained and correlated with the cytological findings wherever available. Results: In the study, 652 cases were included during the 2 years. Out of these, 328 (50.3%) were women and 314 (47.3%) were men. Patient’s ages ranged between 2 92 years with a mean age of 47.4 years. There were 366 (56.1%) cases of ascitic fluid followed by 262 (40.1%) cases of pleural fluid and 24 (3.8%) cases of pericardial fluid in the analysis. Of all the cases, 13 (2%) were non-diagnostic (ND), 464 (71.6%) were negative for malignant (NFM) cells, 16 (2.4%) were atypia of uncertain significance, 31 (4.7%) were suspicious of malignancy, and 125 (19.3%) were malignant. Cellblock was prepared in 65 cases. Lung cancer followed by breast cancer was the most common malignancies involving the pleural effusion and ovarian cancer was the most common cause of peritoneal effusion. ROM for each diagnostic category was 23% for ND, 25% for NFM, 56% for the atypical category, 80.6% in suspicious, and 90% were for positive for malignancy category. Conclusion: The use of a five-tiered system as per the ISRFC and IAC guidelines are feasible for the standardized reporting of effusion samples, thus avoiding subjective variation of reporting.

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

“…Evaluation of pericardial effusions has been reported in 10 studies, five of which reported ROM assessments (Table 1). [20][21][22][23][24][25][26][27][28][29] The number of samples/patients in studies with reported ROM ranged from 64 to 574. The estimated ROM for each category was: ND, 0%-100%; NFM, 1.3%-17.4%; AUS, 0%-35%; SFM, 57.1%-100%; MAL, 89.3%-100%.…”

“…There were 13 studies that included pleural effusions, 10 of which reported ROM evaluation (Table 2). 18,[20][21][22][24][25][26][29][30][31][32][33][34] The number of samples/patients ranged from 350 to 2454. The estimated ROM for each category was: ND, 0%-57.1%; NFM, Eleven studies provide data for peritoneal effusions, and ROM was assessed in seven of them (Table 3).…”

“…The estimated ROM for each category was: ND, 0%-57.1%; NFM, Eleven studies provide data for peritoneal effusions, and ROM was assessed in seven of them (Table 3). 18,[20][21][22][24][25][26]29,31,35,36 The number of samples/patients ranged from 217 to 2257 in studies with reported ROM. The estimated ROM for each category was: ND, 0%-100%; NFM, 1.8%-27.5%; AUS, 22.2%-62.5%; SFM, 80%-100%; MAL, 100%.…”

“…In total, six studies evaluated the TIS categories either without separating the serous effusions into pleural, peritoneal and pericardial when presenting their data or without making that specific distinction when calculating the ROM (Table 4). 19,22,29,[37][38][39] The number of samples/patients ranged from 137 to 1129. The ROM for each category was estimated by in of them: ND, 10% and 23%; NFM, 4.4% and 25%; AUS, 19% and 56%; SFM, 83.3% and 80.6%; MAL, 100% and 90%, respectively.…”

“…There were 13 studies that included pleural effusions, 10 of which reported ROM evaluation (Table 2). 18,20–22,24–26,29–34 The number of samples/patients ranged from 350 to 2454. The estimated ROM for each category was: ND, 0%‐57.1%; NFM, 1.8%‐29.8%; AUS, 33.3%‐62.3%; SFM, 76.2%‐99.3%; and MAL, 90.2%‐100%, excluding the study by Jha et al Notably, in the study by Jha et al 32 the ROM was reported to be considerably high for all categories: 87.5% for ND, 51.61% for NFM and 88.23 for AUS; these findings are discordant with those reported by the other investigators.…”