Etiology of asymptomatic microscopic hematuria in adults.

Asymptomatic microscopic hematuria is a common finding that demands urologic evaluation. Of the 236 patients over the age of 40, 6.8% were found to have a genitourinary cancer, while 27.5% had other significant urologic disease. However, 52.1% of the patients had unknown etiology of microscopic hematuria and 13.6% had insignificant urologic lesions. Of the 72 patients under the age of 40 a positive diagnosis was made in 16 patients (22.2%). Cystoscopic examination was of diagnostic value in only 1 patient. Therefore, cystoscopy is of little diagnostic value in young patients. Once asymptomatic microscopic hematuria is established and no etiological cause is identified, we follow the patient by urinalysis and cytology every three months and reevaluate the patient in whom urological symptoms develop.