Modification of The Paris System for urinary tract washing specimens using diagnostic cytological features

Abstract

TPS is a useful diagnostic system for urinary tract washing specimens by decreasing the number of AUC cases and increasing sensitivity. In this study, anisonucleosis and India ink nuclei improved the diagnostic accuracy of HGUC.

Improved diagnostic precision of urine cytology by implementation of The Paris System and the use of cell blocks

“…The reported effect on sensitivity for diagnosing HGUC has also varied among studies, with some studies reporting an increase in sensitivity and others reporting a decrease in sensitivity . At our institution, the baseline sensitivity, at >80%, is higher than that of the pre‐TPS classification in most other studies, which report 60% to 70% sensitivity for HGUC . In the current study, after careful reclassification of atypical cases to TPS categories, in total, 3 cases were reclassified as NHGUC but demonstrated HGUC on surgical biopsy.…”

“…The current findings demonstrated that TPS and TPS‐like methods improve the performance of urine cytology by lowering the rate of the atypical diagnosis while significantly increasing the PPV of the atypical diagnosis for HGUC. Several recent studies also have reported similar findings . A single study reported an increase in atypical diagnoses (from 3% to 24% in benign cases) and a lowering of specificity; however, that study consisted primarily of voided specimens, which can have more degenerative artifacts that mimic HGUC .…”

“…16 At our institution, the baseline sensitivity, at >80%, is higher than that of the pre-TPS classification in most other studies, which report 60% to 70% sensitivity for HGUC. 11,12 In the current study, after careful reclassification of atypical cases to TPS categories, in total, 3 cases were reclassified as NHGUC but demonstrated HGUC on surgical biopsy. In the pre-TPS-like period, these cases were diagnosed as atypical, revealing large clusters of urothelial cells with overlapping of nuclei and mild cytologic atypia.…”

“…Several recent studies also have reported similar findings. [9][10][11][12][13] A single study reported an increase in atypical diagnoses (from 3% to 24% in benign cases) and a lowering of specificity; however, that study consisted primarily of voided specimens, which can have more degenerative artifacts that mimic HGUC. 14 In our pre-TPS-like period, we diagnosed AUC frequently (up to 48% of the time) and included reactive atypia because of instrumentation, stones, inflammation, and treatment in Abbreviations: AUC, atypical urothelial cells; HGUC, high-grade urothelial carcinoma;…”

A tale of atypia: What can we learn from this?

“…How does the experience of the authors compare with that of other institutions? Not unexpectedly, using a set of standardized criteria resulted in a reduction of the rates of atypical urothelial cells (AUC) from their pre‐Paris values of 6.60% to 41.20% (a 34.6% range) to 5.30% to 26.00% (a 20.7% range) after the implementation of TPS . Most institutions experienced decreases in AUC rates; the sole outlier was an institution with very low pre‐Paris AUC rates …”