Evaluation of AgNOR staining in human bladder transitional cell carcinoma

The aim of this study was to evaluate the diagnostic value of AgNOR (Argyrophilic Nucleolar Organizer Proteins Region) staining in differentiation between malignant and non-malignant lesion, and histological grading of bladder transitional cell carcinoma. We have also showed the rate of AgNOR distribution score in the nuclear of malignant and non-neoplastic cells of bladder epithelium as an important diagnostic marker at light microscopic level. Forty nine paraffin block samples selected from the Pathology Department of Ghaem Hospital including 6 chronic cystitis, 5 transitional cell carcinoma (Grade I), 15 transitional cell carcinoma (Grade II) and 23 transitional cell carcinoma (Grade III). Nucleolar AgNOR dots were studied in epithelial cells of chronic cystitis and transitional cell carcinoma of bladder Grades I, II, III by a light microscope to distinguish the average number of AgNOR dots and their distribution rate in nuclei of 100 cells which had three or more AgNOR dots. There was a significant stepwise increase in the percentage of cells exhibiting nucleoli with at least three or more distinct silver dots in chronic cystitis and transitional cell carcinoma of bladder Grades I, II, III.The counting of AgNOR dots and determining their distribution score are simple, suitable and cheap method to distinguish malignant neoplastic and non-neoplastic lesion of bladder. This method has also a high diagnostic value for grading of bladder transitional cell carcinoma.