One year of experience using the Paris System for Reporting Urinary Cytology

The Paris System for Reporting Urinary Cytology (TPS) was published in November 2015. It focuses on the diagnosis of high-grade urothelial carcinoma (HGUC) and provides criteria with which to define the category of atypical urothelial cells (AUC). The objective of the current study was to compare two 1-year consecutive periods before and after use of TPS.

A total of 1634 and 1814 urine cytology cases, respectively, were analyzed before and after use of TPS. Histological diagnosis within 6 months was available for 330 and 299 cases, respectively.

After use of TPS, the authors reported significantly fewer low-grade urothelial neoplasms (0.94% vs 1.84%; P<.05) and more cases that were suspicious for HGUC (2.09% vs 0.73%; P<.01) compared with before use of TPS. For the AUC category, there was no significant change in frequency noted for before versus after TPS (6.12% vs 5.18%), whereas the rate of detection of HGUC on histology significantly increased after TPS when compared with before TPS (49.02% vs 28.17%; P<.02). For the HGUC category, neither the frequency (4.69% vs 4.47%) nor the risk of malignancy (89.39% vs 91.04% with HGUC on histology) were found to be significantly different when comparing before and after use of TPS.

In the authors' practice, TPS helped to better characterize the categories of AUC, low-grade urothelial neoplasm, and suspicious for HGUC, which were associated with a higher risk of HGUC compared with the authors' previous classification. Cancer Cytopathol 2018;126:430-6. © 2018 American Cancer Society.