Urinary cytology in the detection of bladder carcinoma.

We have analysed the accuracy of cytological examination of voided urine in a population of 265 patients presenting with suspected bladder lesions. Bladder carcinoma was confirmed by tissue histopathology in 51 patients. Of these, 42 were identified correctly by urinary cytology examination. Overall 34 patients were labelled as frankly malignant on cytology, of whom 2 were negative on final histology. 13 patients had been designated as suspicious however with 3 benign on final histological diagnosis. These data give a sensitivity for diagnosis of bladder cancer by urinary cytology of 82%, a specificity of 97%, a positive predictive value of 94%, and a negative predictive value of 96%.