AgNOR staining of cell imprint preparations of human bladder cancer.

OBJECTIVE

To determine the clinical usefulness of argyrophilic nuclear organizer region (AgNOR) staining as applied to cell imprint preparations in bladder cancer.

STUDY DESIGN

The study group consisted of 59 bladder cancers (13 grade 1, 24 grade 2 and 22 grade 3). The staining time, quality of staining, relationship of AgNOR counts to tumor grade and interobserver variations in AgNOR counts were compared in cell imprint preparations and paraffin-embedded tissue sections. Interobserver variation was compared by calculating the coefficients of variation (CVs) and correlation coefficients between two independent observers.

RESULTS

Following an optimal staining time of 30 minutes, the AgNOR dots of cell imprint preparations were highly distinct. In contrast, the optimal staining time was variable, and the AgNOR dots often were observed to aggregate in paraffin-embedded tissue sections. The mean AgNOR count was significantly higher in imprint preparations. AgNOR counts from the imprint preparations showed a stronger relationship to tumor grade. The CVs of AgNOR scores in the cell imprints was significantly smaller, and the correlation coefficient was significantly greater.

CONCLUSION

AgNOR staining of cell imprint preparations is a more objective method than paraffin-embedded tissue sections in human bladder cancer.