Sandbox:Hematuria management

Diagnosis

Urine-based tests

A fresh sample of urine should be dipstick tested for proteinuria (renal disease) or nitrituria (infection). If abnormal the sample should be sent for microbiological assessment (microscopy and culture) and cytology.

Microscopy

Urine cytology

Microscopy is performed on urinary sediment (following centrifuging a fresh urine sample) and can quantify the number of erythrocytes. Advantages Useful for detecting urinary casts (suggesting renal disease) Useful for detecting urinary crystals (suggesting calculous disease) Useful for detecting dysmorphology of red cells (suggesting a glomerular cause of hematuria) Useful for detecting atypical or malignant epithelial cells from a tumour are shed into the urine.

Urine cytology is the ‘gold standard’ urine-based test for detecting cancer. Advantages Cytology is best at detecting poorly differentiated tumours and carcinoma in-situ (with poorly-adhesive grossly abnormal cells). But it has a low sensitivity and specificity for low-grade tumours (that have normal looking adherent cells).

Investigation of the lower urinary tract

Cytoscopy: Flexible cystoscope is useful for the inspection of the urethra and visualization of the bladder mucosa. The detection of an abnormality will require subsequent rigid cystoscopy under anaesthesia, whereby tissue can be obtained or treatment performed.

Investigation of the upper urinary tract

This is controversial for the Investigation of the upper urinary tract cause of hematuria. No single imaging modality has the desired attributes of a high sensitivity and specificity, safety (low radiation exposure), low cost and applicability to lots of patients.

Ultrasound (USS)	Intravenous urography (IVU)	Computed tomography (CT)	Endoscopy/Fluoroscopy	MRI
Advantages Ultrasound of the abdomen and pelvis is safe. It is good at detecting Detecting renal parenchymal lesions (e.g. renal cell carcinoma) For characterizing renal cysts Showing renal calculi For determining ureteric obstruction (Hydronephrosis) Disadvantages USS is poor at detecting small lesions within the collecting system (e.g. UCC of the renal pelvis)	Advantages IVU is good at detecting abnormalities of the urothelium (UCC of the ureter and renal pelvis) and stones. Disadvantages Poor at detecting small renal parenchymal lesions that do not distort the renal outline. It cannot distinguish cystic from solid masses.	Advantages Distinguish equivocal cases, for planning treatment options and determining the nature of small renal parenchymal lesions. Has a high specificity and sensitivity for investigating the causes of hematuria. Disadvantages CT is expensive, time consuming and carries a high radiation exposure.	Advantages Used to investigate intravenous urography filling defects and to treat stones. In patient with continued undiagnosed hematuria, this can be used to collect urine or brushings from each ureter, allowing cytology to determine the site of bleeding and the presence of very small tumors of carcinoma in-situ. Disadvantages Requires general anaesthesia for the procedure.	MRI can been used for equivocal cases and planning treatment.

The initial evaluation of patients presenting with gross hematuria is 3-fold:

• Assess hemodynamic stability
• Determine the underlying cause of hematuria
• Ensure urinary drainage.

Evaluation of patients with haematuria includes a focussed history and physical examination, urinalysis and various blood tests.Most importantly the lower urinary tract should be visualized using cystoscopy, usually using a flexible scope, and the upper tract imaged by a combination of modalities including plain X-ray, ultrasonography, intravenous urography or computed tomography urography.

The treatment options for haematuria depend on the underlying cause.