title: Applying the Paris System for Reporting Urine Cytology Increases the Rate of Atypical Urothelial Cells in Benign Cases: A Need for Patient Management Recommendations.
abstract: The Paris System (TPS) for reporting urinary cytology attempts to unify the terminology in this field.
  
  
  OBJECTIVE
  To analyze the impact of adopting TPS by measuring nomenclature agreement and cytohistological correlation.
  
  
  METHODS
  Voided urine liquid-based cytology samples corresponding to 149 biopsy-proven cases (76 high-grade carcinomas, 40 low-grade carcinomas, and 33 benign lesions), were reclassified by the same pathologist using TPS. Diagnostic agreement and sensitivity for both nomenclature systems was measured.
  
  
  RESULTS
  When using TPS, the rate of atypical samples increased 8 times (from 3 to 24.2%) in benign cases, 10 times (from 2.5 to 25%) in low-grade carcinomas, and 2.4 times (from 6.6 to 15.8%) in high-grade carcinomas. The false-positive rate (abnormal cytology in negative or low-grade carcinoma cases) increased from 11 to 34.2%. Sensitivity was higher (63 vs. 49%) with TPS at the expense of a lower specificity (73 vs. 91%). The agreement between both nomenclatures was moderate for negative and high-grade carcinoma cases (k = 0.42 and 0.56, respectively) and weak for low-grade tumors (k = 0.35).
  
  
  CONCLUSIONS
  Adopting TPS for reporting urine cytology results in a considerable increase in atypical diagnoses, improving sensitivity but lowering specificity. Appropriate management recommendations for patients with an atypical cytological diagnosis are required.
authors.affiliation: Department of Pathology, Hospital Universitario de Getafe, Madrid, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Granados
authors.forename: Joanny A
authors.initials: JA
authors.lastname: Duarte
authors.forename: Teresa
authors.initials: T
authors.lastname: Corrales
authors.forename: Encarnación
authors.initials: E
authors.lastname: Camarmo
authors.forename: Paloma
authors.initials: P
authors.lastname: Bajo
mesh_terms: D001706:Biopsy; D002277:Carcinoma / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D019468:Disease Management; D004847:Epithelial Cells / Q000473:pathology*; D005189:False Positive Reactions; D006801:Humans; D060787:Neoplasm Grading; D009369:Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012107:Research Design; D012680:Sensitivity and Specificity; D009626:Terminology as Topic; D016482:Urinalysis; D001743:Urinary Bladder / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000473:pathology; D019459:Urothelium / Q000473:pathology*