[The Paris System, 2022 edition: What is new?]

Abstract

The second version of the Paris System for reporting urine cytology was published in 2022. It follows the first version of 2016, which was very successful and widely adopted by many cytopathologists from different countries. Thus, numerous publications using the Paris System have made possible to refine the criteria as well as discussing the limits. The diagnostic accuracy of urinary cytology is high for detection of high-grade urothelial carcinoma, but not for low-grade carcinoma where there are few cytological abnormalities. So, the chapter individualizing low-grade urothelial neoplasms was deleted; the latter were included in the category "negative for high-grade urothelial carcinoma". Indeed, the risk of malignancy is replaced by the risk of high-grade urothelial carcinoma. A new chapter has been devoted to urothelial tumors of the upper tract. Finally, the pitfalls linked to cellular degeneration are discussed for each category. The risk of high-grade malignancy associated with each category will help communication with the clinician and help patient care.

Keywords: Carcinome urothélial; Cytologie urinaire; Système de Paris; The Paris System; Urinary cytology; Urothelial carcinoma.