EVALUATION OF NUCLEOLAR ORGANIZER REGIONS IN HUMAN BLADDER CANCERS BYLIGHT-MICROSCOPIC AND ELECTRON-MICROSCOPIC MORPHOMETRY

The number of nucleolar organizer regions (NOR) of human bladder cance rs was evaluated at the light- and electron-microscopic level. The ave rage number of argyrophilic NOR (AgNOR), stained by the one-step silve r colloid method, was measured in benign and malignant urothelial cell s in the human urinary bladder using a light microscope. The average n umber of nucleolar fibrillar centers (FC) per nucleus was also calcula ted by quantitative ultrastructural morphometry in the specimens from the same patients. Statistical evaluations revealed that the average n umber of AgNOR per nucleus was significantly correlated with the eleva tion of tumor grade and stage (p < 0.05). An average FC number per nuc leus also increased in association with tumor grade and stage Cp < 0.0 5). Although the average number of FC was 5.6 times higher than that o f AgNOR, the correlation between the average number of FC and AgNOR wa s statistically significant. In conclusion, these results suggested th at the silver staining method was a useful and convenient tool for the evaluation of the differentiation and invasive potential of bladder c ancer cells at the light-microscopic level.