What is the best course of management for a patient with a history of long-term ibuprofen use, recent gross hematuria and flank pain after abdominal trauma, and a CT urogram showing an irregular filling defect in the left renal pelvis?

Urgent Urologic Evaluation Required for Renal Pelvic Mass

This patient requires immediate urologic referral for cystoscopy and likely ureteroscopy with biopsy of the 1.5 x 2.2 cm irregular filling defect in the left renal pelvis, as this presentation carries a high probability of urothelial carcinoma that demands tissue diagnosis regardless of the trauma history. 1

Critical Clinical Context

The trauma history is a red herring in this case. While the toddler stepping on the abdomen triggered the initial gross hematuria episode, the CT urogram finding of an irregular filling defect measuring 1.5 x 2.2 cm in the left renal pelvis is highly suspicious for malignancy and cannot be attributed to trauma alone. 1 Trauma may have unmasked an underlying pathologic process by causing bleeding from an existing lesion. 1

Why This Cannot Be Dismissed as Trauma-Related

• Blunt renal trauma typically causes parenchymal injury, perinephric hematoma, or collecting system disruption—not discrete filling defects in the renal pelvis. 2
• The resolution of gross hematuria within 4-6 hours followed by discovery of a persistent mass lesion suggests the trauma revealed an underlying pathology rather than caused it. 1
• Gross hematuria carries a 30-40% risk of malignancy in adults and mandates complete urologic evaluation regardless of whether a benign explanation (like trauma) seems plausible. 1

The Ibuprofen Factor: Contributory but Not Causative

The chronic high-dose ibuprofen use (400-2400 mg daily for approximately one year) is clinically significant but does not explain the filling defect:

• NSAIDs can cause acute kidney injury, interstitial nephritis, hematuria, and proteinuria—but they do not cause filling defects or masses in the renal pelvis. 3, 4, 5
• The ibuprofen may have contributed to the severity of hematuria or unmasked the underlying lesion by affecting renal hemodynamics, but it did not create the structural abnormality seen on CT. 3
• Ibuprofen-induced nephrotoxicity typically presents with elevated creatinine, proteinuria, and microscopic hematuria—not with discrete mass lesions. 3, 4

Immediate Action Required on Ibuprofen

Discontinue ibuprofen immediately. 3, 4 The patient's chronic use pattern (up to 2400 mg daily for days at a time over one year) places them at significant risk for ongoing renal injury, and continued use could complicate both diagnosis and treatment of the renal pelvic lesion. 3

Differential Diagnosis for Renal Pelvic Filling Defect

The irregular filling defect in the left renal pelvis has a limited differential diagnosis:

Most Likely: Urothelial Carcinoma (Transitional Cell Carcinoma)

• Urothelial carcinoma of the renal pelvis accounts for 5-10% of all renal tumors and presents as filling defects on CT urography. 1
• The "irregular" morphology described is particularly concerning for malignancy rather than a smooth benign lesion. 1
• Risk factors to assess include smoking history (especially >30 pack-years), occupational exposure to chemicals/dyes (benzenes, aromatic amines), and age >35-40 years. 1

Alternative Diagnoses to Consider

• Blood clot: Could form after trauma, but typically resolves within days and would not persist as a discrete filling defect on delayed imaging. 2
• Fungal ball: Rare in immunocompetent patients; typically seen in neonates or immunocompromised individuals with candidiasis. 2
• Radiolucent stone: Uric acid stones can appear as filling defects, but the ultrasound was reportedly normal and stones typically show some echogenicity. 1
• Sloughed papilla: Can occur with analgesic nephropathy (relevant given chronic NSAID use), but typically presents with acute obstruction and pain. 1

Mandatory Diagnostic Workup

Immediate Urologic Procedures

Cystoscopy with retrograde pyelography and ureteroscopy with biopsy is the definitive diagnostic approach. 1

• Flexible cystoscopy should be performed first to evaluate the bladder for synchronous lesions (present in 2-4% of upper tract urothelial carcinomas). 1
• Retrograde pyelography provides detailed visualization of the collecting system and can confirm the filling defect. 2
• Ureteroscopy allows direct visualization and biopsy of the renal pelvic lesion for tissue diagnosis. 1
• Voided urine cytology should be obtained, as it has high specificity for high-grade urothelial carcinoma. 1

Additional Imaging Considerations

• The CT urogram already performed is the gold standard for upper tract evaluation. 1
• No additional imaging is needed before urologic referral—the priority is tissue diagnosis. 1
• If the patient has not yet had a complete multiphasic CT urogram (unenhanced, nephrographic, and excretory phases), ensure this is completed to fully stage the lesion. 1

Laboratory Evaluation

• Serum creatinine and complete metabolic panel to assess baseline renal function before any intervention. 1
• Complete blood count to evaluate for anemia from chronic bleeding. 1
• Urinalysis with microscopy to document degree of hematuria and assess for other abnormalities. 1

Management Algorithm

Step 1: Immediate Actions (Within 1-2 Weeks)

1. Discontinue ibuprofen immediately and counsel patient on NSAID nephrotoxicity. 3, 4
2. Urgent urology referral (within 1-2 weeks) for cystoscopy and ureteroscopy with biopsy. 1
3. Obtain voided urine cytology before instrumentation. 1
4. Assess renal function with serum creatinine and complete metabolic panel. 1

Step 2: Urologic Evaluation

1. Flexible cystoscopy to evaluate bladder and ureteral orifices. 1
2. Retrograde pyelography to confirm filling defect and assess collecting system. 2
3. Ureteroscopy with biopsy of renal pelvic lesion for tissue diagnosis. 1
4. Consider selective cytology from the left renal pelvis during ureteroscopy. 1

Step 3: Management Based on Pathology

If urothelial carcinoma is confirmed:

• Staging with chest/abdomen/pelvis CT to assess for metastatic disease. 1
• Multidisciplinary discussion regarding nephron-sparing endoscopic management versus nephroureterectomy based on tumor grade, stage, and patient factors. 1

If benign pathology (blood clot, inflammatory lesion):

• Conservative management with surveillance imaging and repeat urinalysis. 2, 1
• Address underlying cause (discontinue NSAIDs, treat any infection). 3

If fungal ball or sloughed papilla:

• Percutaneous nephrostomy for drainage if obstructive. 2
• Antifungal therapy if candidiasis confirmed. 2

Critical Pitfalls to Avoid

Do Not Attribute the Filling Defect to Trauma Alone

The trauma may have caused the initial bleeding, but it does not explain a persistent 1.5 x 2.2 cm irregular filling defect in the renal pelvis. 1 Trauma-related hematuria typically resolves within 48 hours in minor injuries, and the ultrasound was normal. 2

Do Not Delay Evaluation Due to Resolved Symptoms

Even though the gross hematuria and flank pain resolved, the CT finding of a filling defect mandates tissue diagnosis. 1 Urothelial carcinoma can present with intermittent hematuria, and symptom resolution does not exclude malignancy. 1

Do Not Assume Ibuprofen Caused the Mass

While chronic NSAID use can cause multiple renal complications (acute kidney injury, interstitial nephritis, papillary necrosis), it does not create filling defects in the renal pelvis. 3, 4, 5 The ibuprofen should be discontinued, but the filling defect requires independent evaluation. 3

Do Not Perform "Watchful Waiting" Without Tissue Diagnosis

A 1.5 x 2.2 cm irregular filling defect in the renal pelvis is too large and too suspicious to observe without biopsy. 1 Delaying diagnosis of urothelial carcinoma worsens prognosis, as these tumors can progress rapidly. 1

Follow-Up Protocol After Initial Evaluation

If the initial ureteroscopy and biopsy are negative for malignancy but the filling defect persists:

• Repeat ureteroscopy with more extensive sampling in 3-6 months. 1
• Repeat urine cytology every 3-6 months for at least 2 years. 1
• Surveillance CT urography at 6-12 month intervals to assess for growth or change in the lesion. 1

If the filling defect resolves completely (suggesting blood clot):

• Repeat urinalysis at 6,12,24, and 36 months with blood pressure monitoring. 1
• Immediate re-evaluation if gross hematuria recurs or new urologic symptoms develop. 1

Special Consideration: NSAID-Induced Renal Injury

While addressing the filling defect is the priority, the chronic ibuprofen use warrants specific attention:

• Monitor renal function with serum creatinine and estimated GFR at 1 week, 1 month, and 3 months after discontinuing ibuprofen. 3
• Most NSAID-induced acute kidney injury resolves within 7-16 days, but some cases require weeks to months for complete recovery. 3, 4
• Counsel the patient that continued NSAID use could result in irreversible chronic kidney disease. 3
• Provide alternative pain management strategies (acetaminophen, physical therapy, topical agents) that do not carry renal toxicity risk. 3