Evaluation of the patient with asymptomatic microscopic hematuria.

Asymptomatic microscopic hematuria (AMH) is relatively common in clinical practice but the etiology remains unclear in the majority of patients; it is rarely related to genitourinary malignancies. The 2012 guidelines of the American Urological Association recommend an evaluation after a single positive urinalysis with mandatory upper tract evaluation in all patients, preferably with CT urography (CTU). The likelihood of detecting significant upper track abnormalities, particularly malignancies is low with CTU, while incidental extraurinary abnormalities are often found, the majority of which are not clinically significant. The workup for these incidental findings has significant financial and clinical implications. Primary care physicians, who are most apt to encounter patients with AMH, have a low rate of adherence to the AUA guidelines, possibly as a result of the broadening of criteria for AMH evaluation by the AUA, with resultant uncertainty amongst primary care physicians about the appropriate candidates for such evaluation. Selection of subgroups of patients with risk factors for GU malignancies who may benefit from a complete evaluation is essential, as opposed to evaluation of all patients classified as having AMH.