Utility of Urine Cytology in the Workup of Asymptomatic Microscopic Hematuria in Low-risk Patients

Objectives

To evaluate performance and cost-effectiveness of voided cytology in patients with pure asymptomatic microscopic hematuria (AMH). Although voided cytology has been validated for use in patients with a history of urothelial carcinoma (UC), its use in low-risk patients with AMH is controversial.

Methods

A total of 200 consecutive low-risk patients (median age, 64 years) with AMH were referred to the urology clinic between 2005 and 2007. All underwent cystoscopy, upper tract imaging, and voided urinary cytology. Results of voided cytology were classified as positive, atypical, or negative. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and costs were calculated.

Results

None had positive cytology, 23 (11.5%) had atypical cytology, and 177 (88.5%) had negative urinary cytology. Of 200 patients, 8 (4%) were found to have low-grade UC of bladder via cystoscopy; the cytology was negative in 4 patients and atypical in 4. Of 8, 4 were Ta and 4 were pT1 tumors. There was no upper urinary tract or renal malignancy identified. If atypical cytology was considered as positive, the sensitivity, specificity, PPV, and NPV of cytology were 50%, 90%, 17%, and 98%, respectively. If atypical cytology was considered as negative, the sensitivity, specificity, PPV, and NPV of cytology were 0%, 100%, 0%, and 96%, respectively. Cost of performing urinary cytology was estimated at $262.50 per patient.

Conclusions

Although this study supports evaluating patients with AMH because a significant percentage of patients will have UC, voided urine cytology added a significant cost without any diagnostic benefit in the work-up of low-risk patients with AMH.