Patterns of nucleolar organizer region in urinary bladder cancer in view of 2004 WHO classification of urothelial neoplasms

Context: The last decade has seen a tremendous upheaval since introduction of WHO-1998 classification (modified in 2004) of bladder carcinoma, which only recently seems to have settled down. We compare both old (WHO-1973) and new (2004) classifications with argyrophilic nucleolar organizer region (AgNOR) score. Aims: To compare WHO/ISUP (World Health Organization/International Society of Urologic Pathologists) consensus classification-2004 and WHO-1973 classification of bladder carcinoma and to establish correlation between AgNOR scores and various grades of carcinoma bladder. Materials and Methods: Sixty H and E (Hematoxylin and Eosin) stained sections of transitional cell carcinoma bladder were graded according to WHO/ISUP (2004) and WHO (1973) classification systems and the results were compared. This was then followed by AgNOR staining of the paraffin-embedded sections and subsequent AgNOR scores were calculated and given as total score, extranucleolar score, intranucleolar score, and nucleolar score. These were correlated with the grade of the tumor. Statistical Analysis Used: ANOVA test. Results: It was observed that the two grading systems, WHO/ISUP (2004) and WHO (1973) correlated with each other. Also it was observed that the total AgNOR score and extranucleolar AgNOR score increased with the grade of the tumor and thus increasing scores carry significance in assessment of the grade of the tumor. However, intranucleolar and nucleolar scores showed variable degree of overlap in various grades of the bladder tumors. Conclusions: WHO/ISUP (2004) classification correlated well with the WHO (1973) classification. The total AgNOR score was found to be helpful in assessment of the grade of the tumor but the distribution of the AgNOR carried little significance.