The value of urine cytology in the diagnosis of bladder cancer. Cytopathological correlation

OBJECTIVE: To identify the value of urine cytology in the diagnosis of bladder cancer by comparing cytologic and histologic findings.

METHODS: This study was conducted from January to December 2012 at the Department of Pathology, Faculty of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia. The laboratory database was retrospectively reviewed for all patients with a histopathological diagnosis of urothelial carcinoma (UC) between January 2007 and December 2011. Histopathological diagnosis was considered the gold standard, and urine cytology findings were correlated with the results of bladder biopsy. Biopsies with low- and high-grade lesions were considered positive. All data were analyzed using the Statistical Package for Social Sciences.

RESULTS: We reviewed the results of 191 patients. Urine cytology results were positive for malignancy in 70 cases (36.6%) and negative in 19 (9.9%). One hundred and two cases (53.4%) were considered suspicious for malignancy. Histopathological examination revealed that there were 82 cases (42.9%) of low-grade UC, and 64 cases (33.5%) of high-grade UC. Seven cases (3.7%) were positive for malignancies other than UC. For urine cytology, the overall sensitivity was 94.1%, and 26.3% specificity. The sensitivity of urine cytology for low-grade was 18.3%, and 51.3% for high-grade UC. The specificity for both grades was 26.3%.

CONCLUSION: This study shows that sensitivity of urine cytology is higher in high-grade UC than in low-grade UC. The high sensitivity of urine cytology confirms that it is still a valuable tool in bladder cancer diagnosis.