[Characteristics of bladder tumors showing positive urinary cytology--respective analysis in differentiated and undifferentiated type].

: To study the characters of bladder tumors which showed positive urinary cytologies, the results of urinary cytology of untreated bladder tumor patients in our hospital during 10 years between July 1980 and June 1990 were evaluated according to the degree of tumor differentiation, namely differentiated type which did not contain grade 3, and undifferentiated type which contained grade 3. Concerning the differentiated tumors, positive rate of cytology was 37.3% on the whole. Positive rates of multiple tumors or tumors around internal urethral orifice were significantly high, and those of tumors larger than 3 cm, tumors located on posterior wall, left wall or throughout the entire surface, were higher than the overall positive rates. Repeated examinations of yielded increased rates of positive cytology results. Concerning the undifferentiated tumors, the positive rate of cytology was 90.0% on the whole, was not influenced by tumor sizes or locations, and was consistently observed irrespective of the number of times of cytologic examination.