The Paris System “atypical urothelial cells” category: can the current criteria be improved?

Aram Vosoughi, Atousa Ordobazari, Manuel A. Lora Gonzalez, Luiz Paulo Guido, Magdalena Skiba, German Campuzano-Zuluaga, Oleksandr N. Kryvenko, Carmen Gomez-Fernandez, Monica Garcia-Buitrago, Merce Jorda

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Introduction: The Paris System (TPS) for reporting urine cytology was developed for standardization of diagnosis focusing on the detection of high-grade urothelial carcinoma (HGUC). Probably the most challenging task for TPS is to provide criteria for the atypical urothelial cell (AUC) category. The TPS criteria for AUC include increased nuclear/cytoplasmic (N/C) ratio (>0.5) and 1 of the 3 minor criteria including nuclear hyperchromasia (NH), coarse chromatin (CC) and irregular nuclear membrane (INM). We evaluated TPS-AUC diagnostic value and investigated whether other morphologic parameters can improve its criteria. Materials and methods: Urine samples with diagnoses of AUC collected during a 6-month period were re-reviewed. Data captured included N/C ratio >0.5, NH, CC, INM, and 2 additional criteria including enlarged nuclear size (ENS) and the presence of nucleolus (N). ENS was considered when the nucleus was 2 times larger than the urothelial cell or 3 times larger than lymphocyte. Results: By applying the TPS-AUC criteria, the rate of atypia diagnosis reduced in comparison to Pre-TPS (9% versus 13%, P = 0.02). Among the AUC minor criteria, NH was the best criterion with the highest interobserver agreement (IOA) and correlation with HGUC (k = 0.342, r = 0.61, P < 0.001) and strong PPV (93.6%). ENS had the highest PPV (95.8%) and, after NH, had the highest IOA and correlation with HGUC (k = 0.29, r = 0.52, P < 0.001). Conclusion: TPS improves the diagnostic value of urine cytology, particularly in cases with atypia. ENS is a strong criterion for increasing the diagnostic value of AUC and potentially can improve TPS performance as a minor criterion.

Original languageEnglish (US)
Pages (from-to)3-8
Number of pages6
JournalJournal of the American Society of Cytopathology
Issue number1
StatePublished - Jan 1 2021


  • Atypical urothelial cell
  • Cytology
  • High-grade urothelial carcinoma
  • Nuclear size
  • Paris System
  • Urine

ASJC Scopus subject areas

  • Pathology and Forensic Medicine


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