title: Reproducibility of the 1998 World Health Organization/International Society of Urologic Pathology classification of papillary urothelial neoplasms of the urinary bladder.
abstract: OBJECTIVE
  This study assessed the diagnostic agreement and intra- and inter-observer reproducibility of the World Health Organization/International Society of Urologic Pathology Consensus Classification of Urothelial Neoplasms (1998 WHO/ISUP classification) and the 1973 WHO classification.
  
  
  METHODS
  A teaching set with 5 slides of each papillary neoplasm of low malignant potential, low-grade papillary carcinoma, high-grade papillary carcinoma, and a guideline, as well as a study set of 30 slides containing ten cases of each category, were sent to participants. Six pathologists expert in urological pathology reviewed the 30 slides of non-invasive papillary urothelial tumors in the study set. Diagnostic accuracy and reproducibility were evaluated using intra- and inter-rater techniques (kappa statistic).
  
  
  RESULTS
  A moderate to substantial intra- and inter-observer reproducibility was achieved for both the 1998 WHO/ISUP and 1973 WHO classification. The results of the two classification systems were not different statistically ( P>0.05). Reproducibility was lower in low-grade tumors for both classifications.
  
  
  CONCLUSIONS
  The new proposed classification system for non-invasive urothelial neoplasms does not increase the reproducibility. There is still a need for uniformity in grading in order to compare the different studies and therapies and to provide more accurate information for management.
authors.affiliation: School of Medicine, Department of Pathology, Dokuz Eylul University, 35340 Inciralti, Izmir, Turkey. kutsal.yorukoglu@deu.edu.tr
authors.forename: Kutsal
authors.initials: K
authors.lastname: Yorukoglu
authors.forename: Burcin
authors.initials: B
authors.lastname: Tuna
authors.forename: Emel
authors.initials: E
authors.lastname: Dikicioglu
authors.forename: Ender
authors.initials: E
authors.lastname: Duzcan
authors.forename: Aydin
authors.initials: A
authors.lastname: Isisag
authors.forename: Sait
authors.initials: S
authors.lastname: Sen
authors.forename: Ugur
authors.initials: U
authors.lastname: Mungan
authors.forename: Ziya
authors.initials: Z
authors.lastname: Kirkali
mesh_terms: D002291:Carcinoma, Papillary / Q000145:classification / Q000473:pathology*; D006801:Humans; D015203:Reproducibility of Results; D001749:Urinary Bladder Neoplasms / Q000145:classification / Q000473:pathology*; D014944:World Health Organization