The prevalence of asymptomatic microscopic hematuria in adults ranges from 0.19 to 21 percent. Patients with asymptomatic microscopic hematuria or with hematuria persisting after treatment of urinary tract infection also need to be evaluated. Because upper and lower urinary tract pathologies often coexist, patients should be evaluated using cytology plus intravenous urography, computed tomography, or ultrasonography. When urine cytology results are abnormal, cystoscopy should be performed to complete the investigation.
Microscopic hematuria generally is defined as one to 10 red blood cells per high-power field of urine sediment. The American Urological Association (AUA) defines clinically significant microscopic hematuria as three or more red blood cells per high-power field on microscopic evaluation of urinary sediment from two of three properly collected urinalysis specimens. May be associated with urologic malignancy in up to 10 percent of adults.
