CUA: Asymptomatic Microscopic Hematuria (2008)

See AUA Asymptomatic Microscopic Hematuria Guidelines 2016

Background

• Significant microscopic hematuria was defined as ≥ 3 RBCs/hpf on two microscopic urinalysis without recent exercise, menses, sexual activity or instrumentation

Which patients require evaluation for AMH?

• In patients with recent exercise, menses, sexual activity or urethral trauma/instrumentation, a repeat microscopic exam should be done once the contributing factor has ceased. If the subsequent exam is negative, further work-up is not required.
• It should be determined if the patient’s hematuria could be secondary to a glomerular cause. The presence of proteinuria, red cell casts, or dysmorphic red blood cells on microscopic exam and/or an elevated creatinine is suggestive of a glomerular cause of hematuria and these patients should be referred to a nephrologist for further investigation.
• All other patients should be assessed for the need of further evaluation.

Upper tract evaluation

• Upper tract imaging is recommended for all patients with microscopic hematuria
• IVU, US, and CT are acceptable for the evaluation of the patient with microscopic hematuria.
• US is recommended as the first choice for imaging, taking patient safety (ionizing radiation and exposure to i.v. contrast), availability, and cost into consideration. CT and IVU are justified when additional tests are believed to be indicated.

Lower tract evaluation

• The lower urinary tract is evaluated with urinary cytology and cystoscopy.
• Cytology is recommended for all patients with microscopic hematuria
• Cystoscopy is recommended in patients
  • Aged >40
  • With positive or atypical cytology
  • Risk factor(s) for significant disease
    1. Smoking history
    2. Occupational exposure to chemicals or dyes (benzenes, aromatic amines)
    3. History of irritative voiding symptoms
    4. Analgesic abuse with phenacitin
    5. History of pelvic irradiation
    6. Cyclophosphamide exposure

Recommended follow-up of the patient with AMH

• Following a negative evaluation for AMH, 1-3% of patients have been reported to be diagnosed with a urological malignancy within 3 years
• Patients should be followed by their primary care physician with urinalysis, urinary cytology, and blood pressure checks at 6, 12, 24 and 36 months
  • If a patient develops gross hematuria, positive or atypical cytology, or storage irritative voiding symptoms without infection, then repeat urological evaluation is advised.
  • The development of hypertension, proteinuria, or other findings suggestive the finding of glomerular bleeding would necessitate referral to a nephrologist.
  • If none of these occur after 3 years, then routine follow-up for persistent hematuria can be ceased