Pederzoli F, et al. - Considering the possibility that blue light cystoscopy (BLC) using photosensitizing agents improves detection rates of carcinoma in situ (CIS), transurethral biopsies of bladder tumors evaluated with both white light cystoscopy and BLC were retrospectively reviewed (n = 135 samples from 79 patients). Based on the presence/absence of fluorescence under BLC and the final pathological report (CIS/benign/atypical), researchers classified the biopsies. Findings revealed very high sensitivity (92.7%) and negative predictive value (93.5%) of BLC. BLC led to the removal of a number of BLC(+)/atypical lesions (false positive). They identified good interobserver agreement reviewing BLC(+)/atypical lesions. In the diagnosis of CIS, findings still support morphology as the standard criterion in BCL(+) lesions.