Reclassification of urinary cytology regarding The Paris System for Reporting Urinary Cytology with cytohistological correlation demonstrates high sensitivity for high‐grade urothelial carcinoma

Abstract

Background Recently, The Paris System for Reporting Urinary Cytology (TPS) has led to major changes in the approach to evaluate urine cytology and pattern of reporting. The aim of this study was to reclassify urine cytology reports with TPS in order to determine the frequency of abnormal results compared with the previous system; also, we performed cytohistological correlation in abnormal cytological results. Methods In this study, the voided urine specimens from the patients referred to Shiraz University of Medical Sciences affiliated laboratories were retrieved and analyzed using the laboratory's electronic records system; slides prepared from the samples were reviewed by single cytopathologist blindly according to the proposed criteria of TPS. Results Totally, 1842 urine cytology slides from 828 patients were blindly evaluated by TPS criteria and compared with routine urine cytology classification. Then, available cytohistological correlation was done on 99 abnormal urine cytological results from 58 patients. Among the 26 cytology slides with atypical urothelial cell (AUC) in the previous classification, eight (30.70%) slides were downgraded to negative results, and four (15.30%) were upgraded to higher groups. Therefore, through the reclassification of the slides with TPS, 46% of the AUC changed to other groups. Diagnostic accuracy of the TPS classified urine cytology was 78%, including 87.88% sensitivity, 27.27% specificity, 64.44% positive predictive value, and 60% negative predictive value. Conclusion The findings of the present study confirmed the importance and utility of TPS regarding the reclassification of AUC to other groups and its high sensitivity for detecting high‐grade urothelial carcinoma (HGUC).

Risk of malignancy assessment for the Paris System for reporting urinary cytology

“…In our previous study, addressing the impact of the TPS in the “atypical” group we have documented a significant decrease in the proportion of atypical diagnoses 16 . This has also been demonstrated by most other researchers, 21‐23,30,31 thus constitutes the most significant achievement of the TPS implementation. However, Granados et al have reported a raise in the “atypical” diagnoses in benign cases 32 …”

“…However, this referred to a general urinary cytology material, without any inclusion criteria, apart from histology available for correlation. Other groups have reported similar or higher values, although using different study material, 22,24,26,27,30,31 which renders comparison not feasible.…”

Effect of the Paris system for reporting urinary cytology with histologic follow‐up

“…The ROM of each category is very important for the evaluation of the initial TPS, possible modification of TPS in future versions, and better guidance for clinical management. We compared the ROM from our study with other published data in Table 3 18,26‐31 . Based on above methods, it is not a surprise that different, even opposite results were obtained in different institutions.…”

“…We compared the ROM from our study with other published data in Table 3. 18,[26][27][28][29][30][31] Based on above methods, it is not a surprise that different, even opposite results were obtained in different institutions. For example, the frequency of AUC category was reported to decrease significantly in some institution however unaffected in others as shown in Table 4.…”

“…For example, the frequency of AUC category was reported to decrease significantly in some institution however unaffected in others as shown in Table 4. 3,5,6,[17][18][19][20]27,28,[30][31][32][33][34][35][36][37][38][39] 5 | CONCLUSION TPS represents a significant improvement in classification of urinary specimens. By using TPS, we are able to provide a uniform classification system focused on the detection of HGUC.…”