Prevalence of benign microscopic hematuria among women with interstitial cystitis: implications for evaluation of genitourinary malignancy.

OBJECTIVES

To assess the prevalence of benign microscopic hematuria among a cohort of women with clinical interstitial cystitis (IC).

METHODS

A total of 100 women were prospectively assessed for microscopic hematuria with postvoid sterile catheterization. The evaluation for all patients included urine culture, potassium sensitivity test (PST), cystoscopy with hydrodistension under general anesthesia, and symptom assessment with the Pelvic Pain and Urgency/Frequency (PUF) questionnaire.

RESULTS

The mean age +/- SD was 37 +/- 15 years, with no difference noted in those with or without microscopic hematuria (P = 0.71). Microscopic hematuria was present in 24 (24%) of the 100 women. No patient had gross hematuria, positive urine culture, or cystoscopic findings suspicious for malignancy. The mean PUF score was 17 +/- 6. The PST was positive in 92 (92%) of 100 women, and 8 patients had only cystoscopic findings diagnostic of IC. The likelihood of a positive PST or positive cystoscopic findings among patients with microscopic hematuria was similar to that of patients without microscopic hematuria. The PST results correlated with the cystoscopic findings (P < 0.001). Of 36 patients with positive cystoscopic findings, 28 (78%) had a positive PST, and 28 (30%) of 92 with a positive PST had positive cystoscopy findings.

CONCLUSIONS

In this cohort of women with IC, the prevalence of benign microscopic hematuria was 24%. These data suggest that in women at low risk of genitourinary malignancy who have clinical IC, microscopic hematuria may be an incidental finding.