Haematuria (adult)

Haematuria occurs when blood enters the urinary collecting system and is excreted in the urine. There are many aetiologies for haematuria, and they range from benign and transient to gravely concerning. Haematuria can derive from the kidneys, ureters, bladder, prostate (in men), or urethra. Imaging can often be useful to determine the source.

Epidemiology

Malignancy is four times more frequent in macroscopic haematuria than in microscopic haematuria. Macroscopic haematuria is a common presentation of bladder cancer (80%) and renal cancer (~50%) ⁶. Approximately 5% (range 3-6%) of patients with macroscopic haematuria will have a malignancy ⁷.

Pathology

Haematuria can be considered in two main forms:

• frank (macroscopic) haematuria

  • frank haematuria is considered >1 mL of blood in the urine

  • red-coloured urine (more red than brown) or clots in the urine is suggestive of a lower urinary tract source

• microscopic haematuria: be either symptomatic or asymptomatic and is defined as ≥3 red blood cells per high-powered field (HPF) on 2 out of 3 urinalysis specimens ²

Aetiology

There are many causes of haematuria, some of the more common include ^7,8:

• frank haematuria

  • infection, e.g. cystitis, prostatitis, pyelonephritis

  • urolithiasis

  • trauma

  • hydronephrosis

  • malignancy, e.g. renal cell cancer, urothelial cell carcinoma, prostate cancer

• microscopic haematuria

  • renal parenchymal (medical) disease, e.g. glomerulonephritis, interstitial nephritis, Alport syndrome

Treatment and prognosis

Frank haematuria is almost always evaluated clinically, with cystoscopy, and with imaging (e.g. CT urogram).

Imaging workup for microscopic haematuria is controversial. Some academic societies advocate that in the absence of a known benign aetiology (such as vigorous exercise, infection, or menstruation), then a CT urogram is warranted ^3,4. If the patient has known renal disease then an ultrasound of the kidneys and bladder may be more appropriate.

Some feel that the imaging workup in the setting of microscopic haematuria has a high negative rate for malignancy, and suggest that instead of imaging all patients with microscopic haematuria, imaging should be reserved for higher-risk subsets ⁵.

Microscopic haematuria in children has a different treatment algorithm.