What does a positive result for blood cells (2bc) in the urine (hematuria) without evidence of bacteria on urinalysis (UA) mean?

Understanding Hematuria with Blood Cells (2bc) but No Bacteria on Urinalysis

Finding blood cells (2bc) in urine without bacteria on urinalysis requires further evaluation to rule out potentially serious underlying conditions, particularly urologic malignancies, even when asymptomatic.

What This Finding Means

Microscopic hematuria (defined as >3 red blood cells per high-power field) without bacteriuria can indicate several conditions:

• Urologic malignancy: Bladder, kidney, or ureter cancer
• Urolithiasis: Kidney or urinary tract stones
• Glomerular disease: Various kidney disorders
• Benign prostatic hyperplasia: In men
• Interstitial cystitis: Particularly in women with chronic pelvic pain
• Other causes: Trauma, exercise-induced hematuria, medications

Diagnostic Approach

Step 1: Confirm the Finding

• Microscopic confirmation is essential - dipstick testing alone is insufficient 1
• The American Urological Association defines microhematuria as >3 RBC/HPF on microscopic evaluation 1
• A single positive test should be confirmed with repeat urinalysis

Step 2: Risk Assessment

Risk factors for urologic malignancy include:

• Age >35 years
• Male gender
• Smoking history
• History of gross hematuria
• Chemical/occupational exposures
• History of pelvic radiation
• Chronic urinary tract infections
• Analgesic abuse 1

Step 3: Initial Evaluation

1. Detailed history: Focus on risk factors for malignancy, recent activities (exercise, trauma), medications (anticoagulants)
2. Physical examination: Including genitourinary examination
3. Laboratory tests: Serum creatinine, urinalysis with microscopic examination
4. Rule out benign causes:
   • Recent vigorous exercise
   • Menstruation in women
   • Sexual activity
   • Recent urologic procedures
   • Trauma 1

Step 4: Referral Decision

• Gross hematuria: All patients should be referred for urologic evaluation, even if self-limited (30-40% association with malignancy) 1
• Microscopic hematuria: Consider urologic referral for cystoscopy and imaging in the absence of an identifiable benign cause 1
• Patients on anticoagulants: Should receive the same evaluation as those not on anticoagulants 1

Important Considerations

1. Glomerular vs. Non-glomerular Source:

   • Glomerular bleeding: Associated with >80% dysmorphic RBCs, may require nephrology evaluation
   • Non-glomerular bleeding: Associated with >80% normal RBCs, requires urologic evaluation 1

2. Asymptomatic Microscopic Hematuria:

   • Lower but still significant risk of malignancy (0.5-5%) 1
   • Risk increases with age and other risk factors

3. Common Pitfalls:

   • Failure to refer: Only 36% of primary care physicians refer patients with microscopic hematuria to urologists 2
   • False reassurance from self-limited episodes: Even self-limited gross hematuria warrants evaluation
   • Overlooking anticoagulation: Patients on anticoagulants require the same evaluation as those not on anticoagulants 1
   • Assuming UTI without culture confirmation: Always confirm infection with culture and repeat urinalysis after treatment

Follow-up Recommendations

• For patients with isolated hematuria and negative initial evaluation: Follow for development of hypertension, renal insufficiency, or proteinuria 1
• For patients with risk factors: Complete urologic evaluation including cystoscopy and upper tract imaging
• For patients with suspected glomerular disease: Nephrology consultation

Remember that microscopic hematuria without bacteria is a significant finding that should not be dismissed, particularly in patients with risk factors for urologic malignancy.