• Information
  1. Introduction
  2. Etiology
  3. Evaluation
  4. Treatment

A. Introduction

1. Means red blood cells (RBC) in urine
2. Microscopic hematuria is 2 or more (range 1-10) RBC per high power microscope field
3. Routine screening for hematuria is not recommended
4. Any hematuria must be evaluated however to rule out urinary tract malignancy

B. Etiology

1. Common Causes (in decreasing order)
   1. Urinary Tract Infection
   2. Pyelonephritis
   3. Kidney Stone
   4. Cancer: Bladder, Kidney, Prostate
   5. Glomerulonephritis
2. Nonglomerular Hematuria
   1. Lesion along genitourinary tract beyond glomeruli
   2. Main concern is mass lesion (neoplasm), infection, kidney stone (nephrolithiasis)
   3. Renal Cortical Necrosis
   4. Polycystic Kidney Disease
   5. May be microscopic or macroscopic
   6. Neoplasms at least 1cm can be identified with contrast enhanced CT scans [2]
3. Glomerular Hematuria
   1. RBC filtered through glomeruli before entering urine
   2. Acute and chronic glomerulonephritis
   3. IgA Nephropathy is most common glomerulonephritis
   4. Benign familial hematuria - thin basement membrane disease
   5. Hereditary nephritis (Alport's Syndrome)
   6. Typically microscopic hematuria
4. Other
   1. Exercise induced hematuria
   2. Benign (unexplained, idiopathic) microscopic hematuria
   3. Anticoagulation (usually warfarin)
   4. Factitious hematuria (usually macroscopic)

C. Evaluation

1. Urinalysis
   1. Cytology (not early morning specimen) - 3 separate specimens
   2. Microscopic analysis (see below) for casts, protein, crystals
   3. Critical to rule out bladder carcinoma
2. Microscopic Analysis
   1. Isomorphic RBC: nonglomerular hematuria --> helical CT scan (rule out neoplasm)
   2. Acanthocytes or RBC casts: glomerular hematuria --> full evaluation of renal function
   3. No RBC on microscopic: evaluate for myoglobinuria or hemoglobinuria
3. Urine Cytology
   1. Cytologic analysis x 3 serial first morning specimens
   2. Positive cytology should prompt immediate cystoscopy
   3. Negative cytology x 3 but high clinical suspicion usually warrants cystoscopy
4. Computed Tomography (CT)
   1. Standard of care for hematuria evaluation
   2. Thin section CT without contrast intially to identify stones
   3. All cases of hematuria should include CT with contrast and delayed images [2]
   4. Delayed images are used to evaluate complete urological system
   5. Tumors as small as 1cm can be identified
5. Rule out cystitis, prostatitis
6. Evaluation for Stones
   1. Abdominal radiograph will detect ~80% of kidney stones
   2. Renal ultrasound or CT scan will detect remaining stones
7. Retrograde cystourethrogram for further evaluation of urinary system
8. Renal biopsy usually performed if no cause for chronic hematuria discovered

D. Treatment

1. Underlying Cause
2. Bladder Irrigation with 3-Way Foley Catheter for gross hematuria only
3. Cystoscopy with intervention
4. Surgery

References

1. Cohen RA and Brown RS. 2003. NEJM. 348(23):2330
2. Dahl DM, Mueller PR, Young RH. 2004. NEJM. 351(20):2102 (Case Record)