Additional Testing for Microscopic Hematuria
Order a comprehensive urinalysis with microscopic examination of sediment, serum creatinine, urine culture if infection suspected, and assess for proteinuria—then proceed with risk-stratified imaging and cystoscopy based on patient risk factors. 1
Immediate Laboratory Workup
Core Tests for All Patients
- Comprehensive urinalysis with microscopic sediment examination to quantify RBCs per high-power field, identify dysmorphic RBCs (>80% suggests glomerular source), and detect red cell casts 2, 1
- Serum creatinine to assess renal function 2, 1, 3
- Urine dipstick for proteinuria—if positive, quantify with 24-hour urine collection (>500 mg/24 hours warrants nephrology referral) 1
- Urine culture if urinary tract infection is suspected; if positive, treat appropriately and repeat urinalysis 6 weeks after treatment—if hematuria resolves, no further evaluation needed 2, 1, 3
Critical Specimen Collection Details
- Obtain a clean-catch midstream specimen; in uncircumcised men, retract foreskin to expose glans penis 2, 3
- Use catheterized specimen if clean-catch cannot be reliably obtained due to vaginal contamination, obesity, or phimosis 2, 3
Risk Stratification Determines Next Steps
High-Risk Features Requiring Urologic Evaluation
Order voided urine cytology and proceed with cystoscopy plus imaging if patient has any of: 2, 1, 4
- Age >40 years 1
- Smoking history (current or former) 1, 4
- Occupational exposure to benzenes or aromatic amines 1
- History of gross hematuria 1, 4
- Irritative voiding symptoms 1
- History of pelvic irradiation 1
- Analgesic abuse 1
Urine cytology is particularly useful for detecting transitional cell carcinoma and carcinoma in situ, which are the most common malignancies in patients with microscopic hematuria 2, 4. However, cytology should be used as an adjunct to cystoscopy, not a replacement—if malignant or atypical cells are identified, cystoscopy is mandatory 2.
Imaging Selection
- CT urography is the preferred imaging modality for high-risk patients, as it reliably detects renal cell carcinoma, transitional cell carcinoma in the pelvicaliceal system or ureter, urolithiasis, and renal infections 2, 3
- Traditional intravenous urography (IVU) has limited sensitivity for small renal masses and cannot distinguish solid from cystic lesions 2
- Ultrasound alone is insufficient (sensitivity only 50% for significant pathology) 5
Glomerular vs. Non-Glomerular Differentiation
Indicators of Glomerular Source (Nephrology Referral)
Refer to nephrology if any of the following are present: 1
- Dysmorphic RBCs >80% 1
- Red cell casts 1
- Significant proteinuria >500 mg/24 hours 1
- Elevated serum creatinine 1
Non-Glomerular Hematuria
Proceed with urology referral for cystoscopy and upper tract imaging 1, 3
Age-Specific Approach
Patients ≤40 Years Old
- Lower threshold for conservative management if no risk factors present 5
- If microscopic hematuria only: consider non-contrast CT or ultrasound to rule out stones 5
- Add cystoscopy only if gross hematuria is present 5
- Only 1 in 140 patients ≤40 years had malignancy in one series 5
Patients >40 Years Old
- Full evaluation with pre- and post-contrast CT plus cystoscopy regardless of degree of hematuria 5
- 31 of 264 patients >40 years had malignancy in one series 5
Critical Pitfalls to Avoid
- Never attribute hematuria solely to anticoagulation or antiplatelet therapy without complete evaluation—these medications do not cause hematuria, they only unmask underlying pathology 1
- Do not rely on dipstick alone—confirm with microscopic examination showing ≥3 RBCs per high-power field 1
- Patients with <5 RBCs/HPF on three separate urinalyses are unlikely to have significant pathology and may be followed conservatively, but this applies only to low-risk patients 5
- All patients with gross hematuria require urologic evaluation regardless of other factors—gross hematuria has an odds ratio of 7.2 for cancer 1
Follow-Up for Negative Initial Evaluation
If complete evaluation is negative but hematuria persists: 1