The Paris system for reporting urinary cytology improves correlation with surgical pathology biopsy diagnoses of the lower urinary tract

Introduction: The current study seeks to compare both the original diagnoses (OD) and the updated Paris system diagnoses (PD) of urinary cytology specimens to the corresponding surgical pathology (biopsy) diagnoses (SD) to determine which diagnostic paradigm (OD vs PD) has a stronger correlation to the SD. Design: 56 cases from 34 patients that had a malignant SD associated with a corresponding cytology specimen from the same location within up to 90 days of the biopsy procedure were selected. We reviewed the cytology specimens and assigned a PD to each case. We then compared each OD and each PD to the corresponding SD. Correspondence was defined as when the SD had the same result or equal weight as either cytopathologic diagnosis. Results: Of the 47 cases with an available SD, the PD alone corresponded in 32%, both PD and OD corresponded in 26%, neither corresponded in 42%. The OD in isolation did not correspond to the SD in any cases, indicating superior correlation with the PD as compared to the OD (P = 0.0002). Of the 15 cases where the PD corresponded, 11/15 were from the lower tract and the remaining 4 were from the upper tract, indicating superior correlation with the PD in specimens from the lower urinary tract (P = 0.034). In the 27 cases where the PD alone and both the PD and the OD correlated to the SD, 9/27 were from the upper tract and 18/27 were from the lower tract, indicating further support for increased correlation between the cytopathology and biopsy diagnoses in the lower urinary tract above the upper tract (P = 0.032). Conclusion: When applied, the PD has a stronger correlation to the SD, particularly when the biopsies are from the lower urinary tract. Further study with more cases is required to support this significant association.