A Quest for Accuracy: Evaluation of The Paris System in Diagnosis of Urothelial Carcinomas

INTRODUCTION: Urine cytology is an important screening tool of patients for urothelial carcinoma (UC) and follow-up of patients with treated disease. Ease of procurement, cost-effectiveness, and lower turnaround time are the major advantages. OBJECTIVE: To compare current system of reporting (CSR) at our institute with The Paris System (TPS) and analyze utility of urine cytology based on TPS reporting in correlation with urine culture and histopathology. MATERIALS AND METHODS: One-year retrospective study of 90 cases was undertaken wherein cases presenting with painless hematuria and clinically suspicious of UC were included. Urine cytology slides were reviewed and reported with TPS guidelines. These findings were correlated with histopathological diagnosis and urine culture as indicated. Statistical analysis was done using SPSS 17 software. RESULTS: With TPS guidelines, 11.1% and 5.6% cases were reported as high-grade UC (HGUC) and low-grade urothelial neoplasm (LGUN), respectively. Suspicious for HGUC category included 17.8% of cases. The rate of reporting “atypical urothelial cells (AUC)” was significantly lower (11.1%) with TPS on comparison with CSR (16.7%). Histopathological correlation of positive predictive value for HGUC was better (100%) on using TPS when compared with CSR (64.3%). Among 11 cases with microbial growth on urine culture, 9.1% were reported as atypical. Sensitivity and accuracy of TPS in detecting UC were 83.3% and 86.52%, respectively. Both were higher when compared with CSR. CONCLUSION: In comparison to CSR, criteria of TPS limit the AUC category and enhance the sensitivity and accuracy of detecting HGUC. Adopting TPS for urinary cytology will ensure uniformity and accuracy of HGUC diagnosis.