What are the new recommendations for evaluating microscopic hematuria in a 60-year-old man with a prior smoking history?

Evaluation of Microscopic Hematuria in a 60-Year-Old Man with Prior Smoking History

A 60-year-old man with a prior smoking history and microscopic hematuria should undergo a complete urologic evaluation including cystoscopy and upper tract imaging due to his high-risk status for urologic malignancy. 1

Risk Stratification

According to the 2020 American Urological Association (AUA)/Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction (SUFU) guidelines, this patient falls into the high-risk category based on:

• Age ≥60 years (high risk factor) 1
• Prior smoking history (risk factor, with severity depending on pack-years) 1
• Male sex (higher prevalence of significant urologic disease) 1

The prevalence of asymptomatic microscopic hematuria in older men can be as high as 21%, with a higher risk for significant urologic disease compared to other populations. 1

Definition of Microscopic Hematuria

• Microscopic hematuria is defined as ≥3 red blood cells per high-power field (RBC/HPF) on microscopic evaluation of urinary sediment from 2 of 3 properly collected specimens 1
• Dipstick positivity should always be confirmed with microscopic evaluation due to limited specificity (65-99%) 1
• For high-risk patients, a single urinalysis with ≥3 RBC/HPF may warrant full evaluation 1

Recommended Evaluation

Initial Assessment

• Exclude benign causes (exercise, sexual activity, viral illness, trauma, infection) 1
• Assess for signs of primary renal disease:
  • Significant proteinuria
  • Dysmorphic red blood cells or red cell casts
  • Elevated serum creatinine 1

For This High-Risk Patient

1. Upper Tract Imaging:

   • Multiphasic CT urography is preferred to identify hydronephrosis, urinary calculi, and renal/ureteral lesions 1, 2

2. Lower Tract Evaluation:

   • Cystoscopy to evaluate for bladder masses, urethral stricture disease, and benign prostatic hyperplasia 1, 2

3. Laboratory Testing:

   • Urinalysis with microscopic examination
   • Renal function tests
   • Assessment of inflammatory parameters 3

4. Additional Considerations:

   • Urine cytology may be considered if there are risk factors for carcinoma in situ or irritative voiding symptoms 1
   • Referral to nephrology if there are signs of renal parenchymal disease 1

Risk Factors for Urologic Malignancy

This patient has multiple risk factors that increase concern for malignancy:

• Age ≥60 years (high risk)
• Male sex
• Smoking history
• Microscopic hematuria 1, 4

The risk of urologic malignancy in patients with asymptomatic microscopic hematuria can be up to 5%, but is significantly higher in those with risk factors like smoking history and advanced age. 2

Follow-Up Recommendations

• If initial evaluation is negative but microscopic hematuria persists, shared decision-making regarding additional evaluation is recommended 1
• If the patient develops gross hematuria, significant increase in degree of microscopic hematuria, or new urologic symptoms after a negative evaluation, further workup is warranted 1

Important Caveats

• Avoid delaying evaluation in this high-risk patient, as early detection of urologic malignancy significantly impacts mortality and morbidity 1, 4
• Do not rely solely on urine dipstick testing without microscopic confirmation 1
• Do not attribute microscopic hematuria to anticoagulation therapy or benign conditions without appropriate evaluation 2
• Remember that the risk of malignancy increases with the degree of hematuria (number of RBCs per HPF) 1