[Isolated microhematuria: biopsy, yes or no?].

Isolated asymptomatic hematuria is frequently encountered in clinical practice but there are no established recommendations for its evaluation and management. There is controversy regarding which tests are necessary and whether renal biopsy is indicated. In the pediatric population, renal biopsy should be considered if there is evidence of progressive renal disease or when parents are worried about their child's diagnosis or prognosis. In adults, examinations for isolated microhematuria should include exclusion of pharmacological causes, journeys to endemic areas for S. haematobium or tuberculosis, sickle-cell disease, endometriosis and, in patients older than 40 years, kidney, ureteral or bladder cancer. Examination of urinary sediment may help in identifying the origin of microhematuria. If it is decided to perform a renal biopsy, the patient should be carefully informed of the possible complications of renal biopsy, including the possibility of finding normal renal tissue.