What's the next step in management for a patient with hematuria and flank pain after a negative CT scan of the abdomen and pelvis?

Management of Hematuria and Flank Pain After a Negative CT Scan

For patients with persistent hematuria and flank pain after a negative CT scan of the abdomen and pelvis, the next step should be a comprehensive urologic evaluation including cystoscopy, urine cytology, and consideration of CT urography or MR urography to evaluate for non-stone causes of symptoms.

Diagnostic Considerations After Negative CT

When a standard CT abdomen and pelvis is negative in a patient with hematuria and flank pain, several important diagnostic considerations remain:

• Non-stone urologic pathology: A negative CT does not exclude all urologic causes of symptoms
• Intermittent conditions: Some conditions may not be evident at the time of imaging
• Alternative diagnoses: Several conditions can mimic renal colic but are not visible on standard CT

Key Diagnostic Steps

1. Urinalysis reassessment:

   • Confirm presence of hematuria (microscopic or gross)
   • Evaluate for signs of infection (leukocytes, nitrites)
   • Culture if infection is suspected

2. Cystoscopy:

   • The American Urological Association recommends cystoscopy for all patients aged 35 years and older to exclude bladder cancer and other bladder pathology 1
   • Essential for evaluating lower urinary tract sources of hematuria

3. Advanced imaging:

   • CT Urography (CTU): Should be considered when neither stone nor infection explains symptoms 1

     • Better confirms degree of obstruction
     • Can aid in diagnosing radiolucent stones
     • Superior for detecting urothelial lesions

   • MR Urography (MRU): Consider in patients who cannot receive iodinated contrast 2

     • Useful for detecting congenital anomalies and some vascular causes

Differential Diagnosis to Consider

After a negative CT, consider these alternative diagnoses:

1. Vascular causes:

   • Page kidney (subcapsular hematoma causing hypertension) 3
   • Nutcracker syndrome (compression of left renal vein) 4
   • Renal artery dissection or thrombosis

2. Loin Pain Hematuria Syndrome:

   • Rare condition (prevalence ~0.012%)
   • Characterized by severe flank pain and hematuria
   • Diagnosis of exclusion after thorough evaluation 5

3. Papillary necrosis:

   • May not be well visualized on non-contrast CT

4. Urothelial lesions:

   • Small urothelial tumors may be missed on standard CT
   • CTU has higher sensitivity for detecting these lesions 6

5. Intermittent obstruction:

   • Ureteropelvic junction obstruction
   • Passed stone with residual inflammation

Management Algorithm

1. If infection is suspected:

   • Appropriate antibiotic therapy
   • Consider urologic intervention if evidence of obstructive pyelonephritis 1

2. If symptoms persist with negative initial workup:

   • Proceed to CT Urography or MR Urography
   • Cystoscopy with retrograde pyelography if indicated

3. If advanced imaging remains negative:

   • Consider urodynamic studies
   • Evaluate for non-urologic causes (musculoskeletal, gastrointestinal)
   • Consider referral to pain specialist if chronic pain persists

Follow-up Recommendations

• Repeat urinalysis, urine cytology, and blood pressure checks at 6,12,24, and 36 months 1
• Immediate re-evaluation if gross hematuria, abnormal cytology, or new symptoms develop
• Patients with persistent hematuria require continued surveillance even after initial negative evaluation

Important Caveats

• Up to 11% of patients with ureterolithiasis may have no hematuria, while 51% of patients without stones may have hematuria 7
• Absence of hematuria does not exclude urolithiasis, and presence of hematuria is not specific for stones
• Persistent symptoms despite negative imaging warrant further investigation rather than dismissal