Abstract
The cytologic and histologic diagnoses have been compared in 83 non-treated bladder tumours and 26 recurrent tumours after surgical treatment, involving a total of 99 patients. A histologic grading into five groups, based on the cellular characteristics of the tumour, has been used. A further 96 cases with no tumour of the urinary tract have been examined cytologically. Generally speaking the conformity is good. It should be possible to reduce the number of unsatisfactory smears and of indecisive cytologic diagnoses through increased experience and improved techniques. The cytologic diagnosis is useful in the prognostic evaluation of individual cases, particularly respecting tumours with histologically moderate cellular atypia (grade II), which appear to constitute a biologically heterogenous group. The material does not yet permit an appraisal of the accuracy of cytology in the follow-up after radiation treatment. It is quite evident, however, that a recurrence can be detected cytologically long before it has become clinically manifest.