Evaluation of visible hematuria

Visible (gross) hematuria is urine that is visibly discolored by blood or by blood clot. It may present as urine that is red to brown, or as frank blood. As little as 1 mL of blood can impart color to 1 liter of urine. By contrast, nonvisible (microscopic) hematuria is not visible to inspection and is defined as 3 or more red blood cells per high power field on microscopic inspection.

Visible hematuria, even when transient or asymptomatic, may indicate a significant disease process and always requires further investigation. The spectrum of etiologies has a significant age-dependence, whereby the workup of hematuria can differ between children, adults under the age of 35 years, and adults ages 35 years or older.

It is important to give consideration to people at higher risk for urologic malignancy. Visible hematuria is a presenting sign in more than 66% of patients with urologic cancer. [1] Edwards TJ, Dickinson AJ, Natale S, et al. A prospective analysis of the diagnostic yield resulting from 4020 patients at a protocol-driven haematuria clinic. BJU Int. 2006 Feb;97(2):301-5. http://www.ncbi.nlm.nih.gov/pubmed/16430634?tool=bestpractice.com Patients with visible hematuria represent a higher-risk group than those presenting with nonvisible hematuria. [2] Nielsen M, Qaseem A. Hematuria as a marker of occult urinary tract cancer: advice for high-value care from the American College of Physicians. Ann Intern Med. 2016 Apr 5;164(7):488-97. http://annals.org/aim/fullarticle/2484287/hematuria-marker-occult-urinary-tract-cancer-advice-high-value-care http://www.ncbi.nlm.nih.gov/pubmed/26810935?tool=bestpractice.com The sensitivity of visible hematuria in revealing malignancy is significant: 0.83 for urothelial carcinoma of the bladder, 0.66 for ureteric carcinoma, and 0.48 in renal cell carcinomas. [3] Buntinx F, Wauters H. The diagnostic value of macroscopic haematuria in diagnosing urological cancers: a meta-analysis. Fam Pract. 1997 Feb;14(1):63-8. https://academic.oup.com/fampra/article/14/1/63/548718 http://www.ncbi.nlm.nih.gov/pubmed/9061347?tool=bestpractice.com However, note that the oncologic significance of visible hematuria is different for males and females. In men ages >60 years, the positive predictive value of visible hematuria for urologic malignancy is 22.1%, and in women of the same age it is 8.3%. [4] Hicks D, Li CY. Management of macroscopic haematuria in the emergency department. Emerg Med J. 2007 Jun;24(6):385-90. http://www.ncbi.nlm.nih.gov/pubmed/17513531?tool=bestpractice.com

Risk factors for urothelial carcinoma include:

• Male gender

• Age 35 years or older

• Smoking

• Exposures to benzene, aromatic amines, carcinogens, chemotherapy, or high doses of analgesics

• A history of:

  • Irritative voiding symptoms

  • Chronic urinary tract infection

  • Indwelling urinary catheter

  • Pelvic irradiation.