Urinary cytology with acridine orange fluorescence is highly valuable for predicting high-grade upper urinary tract urothelial carcinoma.

OBJECTIVES To evaluate the clinical value of acridine orange fluorescent staining in urinary cytology for the diagnosis of upper urinary tract urothelial carcinoma. METHODS AND MATERIALS A retrospective analysis was conducted with 510 cases of upper urinary tract urothelial carcinoma (UTUC) in terms of the results of acridine orange fluorescence (AO-F) staining of the exfoliated cells in urine. The percentage of positive AO-F result and the positive predictive value of AO-F for high-grade and muscle invasive urothelial carcinoma were calculated and analyzed in terms of clinical characteristics. RESULTS The overall percentage of positive AO-F result was 49% in the 510 patients, 54.1% for males and 40.6% for females. AO-F was positive in 51.9% of the patients with hematuria and 36.2% of the patients without hematuria. AO-F was positive in 56.4% of the patients with renal pelvis carcinoma and 42.8% of the patients with ureteral cancer; in 44.6% of the patients with non-muscle invasive carcinoma and 53.5% of the patients with muscle-invasive carcinoma. AO-F was positive in 26.8% of the cases with low-grade carcinoma and 55.3% of the patients with high-grade carcinoma. The positive predictive value of AO-F was 88% for high-grade cancer, and only 53.6% for muscle invasive carcinoma. CONCLUSIONS Acridine orange fluorescence microscopy cannot increase the sensitivity of urine exfoliative cytology in the diagnosis of UTUC. It may be used as a predictor of high-grade UTUC. Acridine orange fluorescence microscopy in urinary cytodiagnosis does not show high value in predicting muscle invasive UTUC.