What could be the cause of an elderly female patient's lower abdominal pain, nocturia, and urinary urgency, with a urine test showing hematuria, proteinuria, and negative leukocytes?

Differential Diagnosis: Hematuria and Proteinuria Without Pyuria in an Elderly Female

This presentation—lower abdominal pain, nocturia, urgency, with hematuria and proteinuria but negative leukocytes—does NOT represent a urinary tract infection and should not be treated with antibiotics. The absence of pyuria (negative leukocyte esterase) effectively rules out bacterial UTI with excellent negative predictive value (82-91%), and antibiotics in this setting cause harm without benefit 1.

Why This Is NOT a UTI

The negative leukocyte esterase is the critical finding that excludes bacterial infection:

• Both negative leukocyte esterase AND negative nitrite have 90.5% negative predictive value for UTI, effectively ruling out bacterial infection in most populations 1
• The absence of pyuria can exclude bacteriuria with nearly 100% negative predictive value 2
• Pyuria (≥10 WBCs/HPF or positive leukocyte esterase) PLUS acute urinary symptoms are BOTH required to diagnose and treat UTI 1
• Never treat based on symptoms alone without laboratory confirmation of pyuria—the combination of negative leukocyte esterase with negative nitrite makes bacterial UTI extremely unlikely regardless of symptoms 1

What This Likely Represents

The combination of hematuria + proteinuria + lower urinary tract symptoms without infection suggests:

Primary Considerations:

1. Bladder pathology (most likely given age and symptoms):

• Bladder mass/carcinoma (presents with painless or painful hematuria, urgency, frequency in elderly women) 2
• Bladder calculi (causes hematuria, urgency, suprapubic pain) 3
• Immediate action required: CTU (CT urography) is the primary test for comprehensive evaluation of hematuria with urinary symptoms in patients >50 years, as it identifies renal and urothelial lesions with excellent sensitivity and specificity 2

2. Glomerular disease:

• The combination of hematuria + proteinuria suggests glomerular origin rather than lower tract bleeding 4
• Nutcracker syndrome can present with hematuria and proteinuria in elderly patients, though typically with more severe anemia 5
• Requires: Renal function assessment, quantification of proteinuria (24-hour collection or protein-to-creatinine ratio), and nephrology referral if proteinuria is significant 4

3. Overactive bladder with incidental findings:

• Up to 40% of elderly patients have lower urinary tract symptoms (urgency, nocturia, frequency) from overactive bladder detrusor, not infection 3
• The hematuria and proteinuria may be coincidental findings requiring separate evaluation 6

Immediate Management Algorithm

Step 1: Stop any antibiotic therapy immediately 1

• Discontinuing antibiotics immediately avoids unnecessary harm, cost, and antimicrobial resistance when there is no evidence of UTI 1
• Continuing antibiotics for non-infectious conditions provides no clinical benefit and increases adverse outcomes 1

Step 2: Obtain proper imaging for hematuria evaluation:

• CTU (CT urography) is indicated for patients >50 years with hematuria and risk factors for urinary tract malignancy 2
• CTU includes unenhanced, nephrographic, and excretory phases, providing detailed anatomic depiction of kidneys, collecting systems, ureters, and bladder 2
• This identifies bladder masses, calculi, obstruction, and congenital anomalies 2

Step 3: Quantify proteinuria:

• Obtain 24-hour urine collection or spot urine protein-to-creatinine ratio 4
• If proteinuria is >1 gram/day, nephrology referral is warranted for glomerular disease evaluation 4

Step 4: Cystoscopy consideration:

• If CTU shows bladder abnormality or hematuria persists, cystoscopy with biopsy is diagnostic for bladder pathology 2
• Cystoscopy can directly visualize bleeding source and obtain tissue diagnosis 2

Critical Pitfalls to Avoid

Do NOT treat with antibiotics based on symptoms alone:

• Elderly women frequently have lower urinary tract symptoms (urgency, frequency, nocturia) from non-infectious causes including overactive bladder, which affects up to 40% of women over 50 3
• Asymptomatic bacteriuria occurs in 15-50% of elderly women and should never be treated 2, 6
• The absence of pyuria definitively excludes bacterial UTI—treating without pyuria only promotes antimicrobial resistance 1

Do NOT dismiss hematuria as "just a UTI":

• Hematuria with proteinuria in elderly patients requires malignancy evaluation until proven otherwise 2
• Bladder cancer commonly presents with irritative voiding symptoms mimicking UTI 2

Do NOT delay imaging:

• CTU should be performed promptly in patients >50 years with unexplained hematuria, as delayed diagnosis of malignancy worsens outcomes 2

When to Reconsider UTI Diagnosis

Only pursue UTI workup if the patient develops:

• Fever >38.3°C (101°F) with systemic signs 1
• Acute worsening of dysuria that persists regardless of hydration 7
• Suprapubic tenderness or costovertebral angle pain of acute onset 6
• AND obtain repeat urinalysis showing pyuria (≥10 WBCs/HPF or positive leukocyte esterase) before starting antibiotics 1