[Microscopic hematuria. Semiologic value in urology. Management of microscopic hematuria].

Microscopic hematuria, a frequent cause for consultation, poses a problem regarding its significance. It is essential that a curable pathology is not neglected. In the absence of associated clinical data, nephrological orientation of investigations depends on the study of urinary sediments and phase contrast microscopy. Where there is a urological orientation, half the lesions involve the lower urinary tract; the use of flexible urethrocystoscopy has been a true advance in terms of its simplicity and reliability. When a lesion is demonstrated the question still remains as to whether it is in fact responsible for the microscopic hematuria. It is best to remain prudent when a poorly significant lesion is discovered. Since 20% of microscopic hematurias remain unexplained, how far should one go in the paraclinical investigation and follow up of involved patients?