Reproducibility of the 1998 World Health Organization/International Society of Urologic Pathology classification of papillary urothelial neoplasms of the urinary bladder.
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.
Yorukoglu
Kutsal
K
School of Medicine, Department of Pathology, Dokuz Eylul University, 35340 Inciralti, Izmir, Turkey. kutsal.yorukoglu@deu.edu.tr
Tuna
Burcin
B
Dikicioglu
Emel
E
Duzcan
Ender
E
Isisag
Aydin
A
Sen
Sait
S
Mungan
Ugur
U
Kirkali
Ziya
Z
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