Voided urine cytology and low-grade urothelial neoplasia of the bladder: factors that influence the sensitivity

IntroductionThe aims of this study were to show the 10-year results of voided urine cytology (VUC) performed using liquid-based cytology (LBC) with CytoRich Red and to discuss the factors that influence the sensitivity of low-grade urothelial neoplasia (LGUN) of the urinary bladder.Materials and methodWe calculated the sensitivity of VUC in 421 histologically confirmed cases included in the pathology database of Hokkaido Cancer Center in Japan and studied various factors influencing sensitivity.ResultsThe cumulative sensitivity of VUC was 95.8% in 143 cases of primary high-grade urothelial carcinomas, compared with 59.5% in 74 cases of LGUN. These findings were only slightly different from the previous results of Koss et al. The sensitivity in LGUN, however, showed lower values in some conditions, including in secondary cases, with a lower frequency of examinations and smaller tumor volumes. LBC preparations allowed us to observe a greater number of tumor cells and cell clusters than conventional methods in LGUN cases.ConclusionsThe sensitivity of VUC can be improved by increasing the frequency of examinations and adopting a valid preparation method in order to augment the number of cells and cell clusters on individual glass slides. LBC preparations may allow cytopathologists to obtain a better sense for and understanding of the cytologic findings of LGUN.