Hematuria Evaluation

Hematuria 101 - Red Flag Rules

• Definition: >3 Red Blood Cells (RBCs) per High Power Field (HPF).
• Types:
  • Microscopic: Asymptomatic, incidental finding.
  • Macroscopic (Gross): Visible blood in urine.
• Initial Sort:
  • Glomerular: Dysmorphic RBCs, RBC casts.
  • Non-glomerular: Eumorphic RBCs, no casts.
• ⚠️ Red Flag Rules (Suspect Malignancy):
  • Painless gross hematuria.
  • Age >40 years.
  • Smoking history.
  • Occupational exposure (aniline dyes, benzenes).
  • History of urologic disease/instrumentation.
  • Persistent asymptomatic microscopic hematuria.

⭐ The presence of RBC casts in urine is pathognomonic for glomerular hematuria.

Etiology Maze - Source Sleuthing

• Glomerular (Nephrologic): Dysmorphic RBCs, RBC casts, proteinuria.
  • IgA Nephropathy (Berger's)
  • Post-Streptococcal GN (PSGN)
  • Alport Syndrome
  • Thin Basement Membrane Disease
  • Lupus Nephritis
• Non-Glomerular (Renal):
  • Neoplasms: Renal Cell Carcinoma (RCC)
  • Infections: Pyelonephritis
  • Stones (Nephrolithiasis)
  • Polycystic Kidney Disease (PKD)
  • Trauma, Vascular (AVM, infarct)
  • Papillary Necrosis (DM, Sickle Cell, 📌 Analgesics)
• Urologic (Lower Tract):
  • Bladder: UTI, Stones, TCC
  • Prostate: BPH, Prostatitis, Cancer
  • Urethra/Ureters: Stricture, Stones, Trauma, TCC
• Other Causes:
  • Coagulopathy, Anticoagulants
  • Vigorous exercise
  • Drugs (e.g., Cyclophosphamide)

⭐ In adults > 40 years, painless gross hematuria is a strong indicator of malignancy (e.g., bladder cancer) and requires thorough investigation.

Clinical Detective - Clue Collection

• History is Key:
  • Hematuria Type: Gross/Microscopic; Initial, Terminal, Total; Clots; Color (red vs. cola).
  • Symptoms: Pain (flank, dysuria), Fever, Weight loss. Systemic (rash, joint pain).
  • Risk Factors: Age >40, Smoking, Occupation (dyes), Meds (anticoagulants, cyclophosphamide 📌), Family Hx (cancer), URI, Trauma, Exercise.

    ⭐ A history of cyclophosphamide use is a significant risk factor for hemorrhagic cystitis and bladder cancer.

• Physical Exam Pointers:
  • General: Pallor, Edema, Lymphadenopathy.
  • Abdomen: Masses, CVA tenderness.
  • GU: Meatal stenosis; DRE (prostate); Pelvic exam.
  • BP: Hypertension.

Diagnostic Toolkit - Scope & Scan

• Imaging (Upper Tract):
  • CT Urography (CTU): Multi-phasic (non-contrast, nephrographic, excretory).

    ⭐ CT Urography is the gold standard imaging for evaluating upper tract causes of hematuria, especially when malignancy is suspected.

  • MR Urography (MRU): If CTU contraindicated (e.g., contrast allergy, pregnancy, radiation).
  • Ultrasound (KUB): Initial, non-invasive; detects stones, hydronephrosis, large masses.
• Endoscopy:
  • Cystoscopy: Mandatory for gross hematuria & high-risk microscopic hematuria.
    • Direct visualization of bladder & urethra.
    • Biopsy capability.
    • Types: Flexible (outpatient), Rigid (OR). Enhanced: Blue light / NBI.
  • Ureteroscopy (URS): If upper tract lesions suspected on imaging or for biopsy.
• Urine Cytology:
  • Adjunct for high-risk patients to detect malignant cells. Not standalone.

High‑Yield Points - ⚡ Biggest Takeaways

• Painless gross hematuria in those >40 years strongly suggests urothelial cancer; mandates CT urogram & cystoscopy.
• Hematuria localization: Initial (urethral), terminal (bladder neck/prostatic), total (bladder/upper tract).
• Microscopic hematuria (≥3 RBCs/HPF on ≥2 occasions) or any gross hematuria needs full workup.
• Glomerular indicators: Dysmorphic RBCs, RBC casts, significant proteinuria point to renal origin.
• Gold standard evaluation: CT urogram for upper tracts, cystoscopy for lower tracts.