Impact of Implementing Paris System on Diagnostic Precision and Management of Urinary Bladder Neoplasms

The diagnosis of atypia has always been under question both by the pathologist and the clinician. It was one of the main aims of the Paris system (TPS) to reduce the number of cases under the AUC (Atypical urothelial cells) category. With the strict criteria laid down by the Paris system, the rate of diagnosis of this category has reduced markedly. This study was done to test the impact of implementing TPS categories and criteria in comparison to our previously used system. TPS is one of the important deciding factors for the management of the patient. The management of patients with AUC diagnosis often varies depending on the treating physician (urologist/nonurologist). For further categorization of the diagnosis of AUC, markers like p53 and Ki67 can be used. One hundred urinary cytology specimens received for the period of 6 months were included in the study. The presentation of the categorical variables was done in the form of numbers and percentages (%). Interrater kappa agreement was used to find out the strength of the agreement between the Paris system and the traditional system. Using histopathological diagnosis as the gold standard, sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic accuracy were calculated. Immunohistochemistry was performed on the cell block for Ki67 and p53, and their values were correlated with histopathological examination, using Spearman’s rank correlation. The interrater kappa agreement analyzed between the traditional reporting system and the Paris system was 0.522. Around 32% (6/19) of cases that were reported as AUC by the traditional system were recategorized under negative for high-grade urothelial carcinoma (NHGUC) by the Paris system. Thus, obliviating the need for further management and decreasing the unnecessary cost of the health care system with a decrease in patient anxiety. Histopathology was available in 28 cases and diagnostic accuracy of urine cytology classified by TPS was 89.2% with a sensitivity of 94.4%, specificity of 80%, positive likelihood ratio of 89.4, and negative likelihood ratio of 88.6. The correlation coefficient of p53 with grading of carcinoma was found to be strong at 0.864. The correlation coefficient of Ki67 with grading of carcinoma was also as strong as 0.885. TPS along with immunohistochemistry improves the performance of urine cytology by reclassifying the AUC category into other groups and increases the sensitivity for detecting