Positive urinary cytology after tumor resection: an indicator for concomitant carcinoma in situ.

Concomitant urothelial atypia (grade II atypia or carcinoma in situ) is predictive of new tumor growth after transurethral tumor resection. Concomitant urothelial atypia can be demonstrated by pre-selected site mucosal biopsies. However, a number of patients have new tumors despite normal pre-selected site biopsies. To investigate whether urinary cytology is a better indicator for concomitant urothelial atypia than pre-selected site biopsies, we studied in bladder tumor patients the correlation between the findings of pre-selected site biopsies (8 per patient) at tumor resection and urinary cytology (2 per patient) after successful resection. Concomitant urothelial atypia was demonstrated by biopsies in 52 per cent of the patients, of whom 60 per cent had grade II atypia and 40 per cent had carcinoma in situ. All patients with concomitant carcinoma in situ in biopsies had positive cytology findings. Of the patients with concomitant grade II atypia in biopsies 15 per cent had negative cytology studies. In 48 per cent of the patients no urothelial atypia in pre-selected site biopsies was demonstrable. However, cytology was positive, that is neoplastic cells were present, in 64 per cent of these specimens (19 patients). Of the 19 patients 16 currently have had demonstrable urothelial atypia in pre-selected site mucosal biopsies at a later occasion. We conclude that urinary cytology seems to be a better indicator for the presence of concomitant urothelial atypia than pre-selected site mucosal biopsies and, therefore, it can be used as a screening procedure for patients without demonstrable concomitant carcinoma in situ at tumor resection.