In order to evaluate flow cytometric deoxyribonucleic acid measurement (FCM) of bladder washing in the diagnosis of bladder carcinoma, the sensitivity of voided urine cytology, bladder washing cytology and bladder washing FCM was tested in 76 samples from 56 patients with histologically proven bladder carcinomas. The positive rates were 43.2% and 75.7% in bladder washing cytology and bladder washing FCM, respectively. On the other hand, 36.5% and 57.1% positive rates for once-and

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... ded urine cytology, respectively, were obtained. Bladder washing cytology and bladder washing FCM were positive in 20% and 70% patients with a histological diagnosis of atypia or dysplasia, respectively. The sensitivity of bladder washing FCM according to the tumor grade was 33.3%, 81.9% and 88.9% for grade-1 (G-1), G-2 and G-3 tumors, respectively. The sensitivity of bladder washing cytology according to the tumor grade was 0, 40.9% and 77.8% for G-l, G-2 and G-3 tumors, respectively. The sensitivity of three-times-voided urine cytology was 25.0%, 55.6% and 83.3% for G-1, G-2 and G-3 bladder tumors, respectively, and it was superior to that of single bladder washing cytology. These results indicate that FCM is more sensitive than voided urine cytology and/or bladder washing cytology in patients with bladder carcinoma. FCM may indicate urothlial neoplasia before it is apparent on urine cytology, especially against a background of inflammation. Therefore, FCM is valuable for case finding in suspect populations or for follow-up cases with diagnosed bladder cancer.