Urinary cytology for carcinoma in situ of the urinary bladder.

The urinary cytologies of 14 nonpapillary carcinomas in situ of the urinary bladder were reviewed. Cytologic malignancy was often diagnosed before any clinical manifestation or cytoscopic lesion could be perceived. The cytologic characteristics of this lesion as previously described in the literature were confirmed: the background was usually clean and the tumor cells were numerous and relatively monomorphic, with many atypias. Taking into consideration the limitations discussed, urinary cytology should be regarded as having great accuracy in the early diagnosis of in situ carcinoma of the urinary bladder.