DIAGNOSTIC-VALUE OF BLADDER WASH CYTOLOGY, WITH SPECIAL REFERENCE TO LOW-GRADE UROTHELIAL NEOPLASMS

The diagnostic yield of bladder wash cytology was compared with concur rent bladder biopsy results in 253 consecutive cytology specimens obta ined from 208 patients. There was high diagnostic concordance of washe s and biopsies for both high grade urothelial neoplasms (26 of 29 case s [90.0%]) and negative specimens (152 of 168 cases [90.5%]). In contr ast, bladder wash cytology was interpreted as malignant or suspicious for malignancy in II of 33 (33%) patients with low-intermediate grade papillary urothelial tumors on biopsy. Additionally, the cytology wits considered positive or suspicious for transitional cell carcinoma in 11 cases in which only reactive changes were seen in the concurrent bi opsy and follow-up studies (minimum 12-month follow-up), for a false-p ositive rate of 6.5%. The slides from all discrepant cases were review ed, with particular attention to background features that may improve the diagnostic sensitivity of cytology in low grade neoplasms.