What is the best course of treatment for a 30-year-old obese male with gross hematuria, joint pain, and normal creatinine (kidney function test) levels, complete blood count (CBC), and blood uric acid levels?

Diagnostic Workup for Gross Hematuria with Joint Pain in a Young Obese Male

This patient requires urgent urologic evaluation with cystoscopy and CT urography to rule out malignancy, despite his young age, because gross hematuria carries a 30-40% risk of underlying malignancy and should never be ignored. 1, 2

Immediate Diagnostic Priorities

Urologic Evaluation (Primary Concern)

• Gross hematuria mandates urgent urologic referral even in a 30-year-old, as malignancy accounts for 30-40% of gross hematuria cases. 1, 3
• The combination of gross hematuria with joint pain does not exclude malignancy—these symptoms can coexist independently. 1
• CT urography (multiphasic with IV contrast) is the preferred imaging modality to comprehensively evaluate the upper urinary tract for renal cell carcinoma, transitional cell carcinoma, and urolithiasis. 1, 2
• Cystoscopy is mandatory to evaluate the bladder for transitional cell carcinoma, which is the most frequently diagnosed malignancy in hematuria cases. 1, 2
• Do not delay urologic evaluation even if the hematuria resolves spontaneously—self-limited gross hematuria still requires complete workup. 2

Distinguish Urologic vs. Glomerular Source

• Examine urinary sediment for dysmorphic RBCs (>80% suggests glomerular disease) and red cell casts (pathognomonic for glomerulonephritis). 1
• Check for significant proteinuria using spot urine protein-to-creatinine ratio (normal <0.2 g/g)—significant proteinuria with hematuria strongly suggests glomerular disease. 1
• The presence of normal creatinine does not exclude glomerular disease in early stages. 1

Joint Pain Evaluation (Secondary but Important)

Rule Out Crystal Arthropathy

• Despite normal serum uric acid, gout cannot be excluded—serum uric acid behaves as a negative acute phase reactant and may be normal or even low during acute attacks. 4
• Normal uric acid levels occur in patients with crystal-proven gout, particularly during acute inflammatory episodes when renal excretion increases. 4
• Joint aspiration with synovial fluid analysis for monosodium urate crystals is the gold standard for gout diagnosis (sensitivity 84%, specificity 100%). 4
• The combination of obesity, joint pain, and hematuria raises concern for metabolic syndrome-associated conditions. 4

Consider IgA Nephropathy

• IgA nephropathy classically presents with gross hematuria concurrent with or immediately following upper respiratory infection or exercise, often with joint pain (Henoch-Schönlein purpura variant in adults). 1
• This diagnosis would explain both the hematuria and joint symptoms in a young patient. 1
• Requires nephrology referral if urinary sediment shows dysmorphic RBCs or proteinuria develops. 1

Specific Laboratory Workup

Essential Initial Tests

• Complete urinalysis with microscopic examination to quantify RBCs, assess for dysmorphic RBCs, red cell casts, and proteinuria. 1, 2
• Urine culture to definitively exclude urinary tract infection (though less likely given joint symptoms). 2
• Spot urine protein-to-creatinine ratio to quantify proteinuria. 1
• Serum creatinine and eGFR to establish baseline renal function. 1, 2

Additional Tests Based on Findings

• If dysmorphic RBCs or proteinuria present: complement levels (C3, C4), ANA, ANCA, anti-GBM antibodies. 1
• 24-hour urine collection for calcium and uric acid excretion if urolithiasis suspected (can cause both hematuria and joint pain from hyperuricemia). 4, 1
• Joint fluid aspiration if joint effusion present—do not rely on serum uric acid alone. 4

Clinical Algorithm

1. Confirm gross hematuria is true hematuria (not menstrual contamination, myoglobinuria, or food dyes). 1
2. Immediate urologic referral for cystoscopy and CT urography—do not wait for other test results. 1, 2
3. Simultaneously evaluate urinary sediment for glomerular vs. non-glomerular source. 1
4. If dysmorphic RBCs >80%, red cell casts, or significant proteinuria present: add nephrology referral. 1
5. Evaluate joint pain with synovial fluid analysis if effusion present, regardless of serum uric acid level. 4
6. Assess for metabolic syndrome components (obesity already present)—check fasting glucose, lipid panel, blood pressure. 4

Critical Pitfalls to Avoid

• Never attribute gross hematuria to a benign cause without complete urologic evaluation—even identified benign causes (stones, infection) do not exclude concurrent malignancy. 1, 2
• Do not be falsely reassured by normal serum uric acid—up to 43% of acute gout patients have normal levels during attacks. 4
• Do not delay urologic referral to "watch and wait"—gross hematuria requires urgent evaluation regardless of patient age. 1, 2
• Anticoagulation or antiplatelet therapy (if present) does not explain hematuria—these medications may unmask underlying pathology but are not the cause. 1, 2
• Young age does not eliminate malignancy risk—while less common under 40, urologic cancers still occur and gross hematuria mandates evaluation. 5

Follow-Up Strategy

• If initial urologic and nephrologic workup is negative, repeat urinalysis at 6,12,24, and 36 months. 4, 1
• Monitor blood pressure at each visit. 1
• Immediate re-evaluation if gross hematuria recurs, irritative voiding symptoms develop, or proteinuria/hypertension emerges. 4, 1