Abstract
300 patients have been studied by means of a fluorescence exfoliative urinary cytology procedure based on the fluoro chromatic properties and the affinity of acridine orange for the nucleic acids. The patients were divided into two groups: in the first group including 238 cases we tried to establish the correlation between the urinary cytological grade and the histological grade of malignancy on biopsy;the rate of accuracy was approximately 77% for low-grade and approximately 88% for the high-grade tumours. In the second group including 62 cases we studied the value of cytology in predicting recurrences;38 and 66.6% of the cases with grades IV and V, respectively, developed recurrences thus confirming the necessity of cytologic controls in patients under conservative treatment. The overall rate of accurate cytological diagnosis with this staining method has reached 90%.