From the Guidelines
The most appropriate diagnostic test to perform next is A. Cystoscopy. This patient presents with a single episode of gross hematuria with microscopic confirmation (10-15 erythrocytes/hpf) but has a normal CT urogram. Cystoscopy is indicated to evaluate the bladder and urethra for potential sources of bleeding that may not be visible on CT imaging, such as bladder tumors, vascular lesions, or inflammatory changes. The patient's normal protein-creatinine ratio and absence of proteinuria on urinalysis make glomerular causes less likely, so kidney biopsy (option B) would be premature. A repeat urinalysis (option C) would not provide additional diagnostic information at this point since hematuria has already been confirmed. The 24-hour urine protein measurement (option D) is unnecessary given the already normal random urine protein-creatinine ratio. In a 43-year-old man with gross hematuria, ruling out urological malignancy is a priority, making cystoscopy the appropriate next step in evaluation, as supported by the American College of Radiology Appropriateness Criteria for hematuria 1 and the American College of Physicians' advice for high-value care in evaluating hematuria 1. Given the potential for malignancy, especially in patients over 40 years old, cystoscopy is a crucial diagnostic step, as emphasized by the American Urological Association's best practice policy recommendations for asymptomatic microscopic hematuria 1.
From the Research
Diagnostic Approach
The patient presents with gross hematuria, which is a significant symptom that requires further evaluation. Given the patient's age and lack of risk factors, the most appropriate next step is to investigate the cause of the hematuria.
Considerations for Diagnostic Tests
- The patient has already undergone a contrast-enhanced CT urogram, which showed no stones, masses, or cysts.
- The urinalysis results show 10-15 erythrocytes/hpf, indicating microscopic hematuria.
- The random urine protein-creatinine ratio is 20 mg/g, which is within normal limits.
Appropriate Diagnostic Test
Based on the studies, cystoscopy is the most appropriate diagnostic test to perform next.
- According to 2, cystoscopy is recommended for adults 35 years and older with gross hematuria.
- Study 3 states that cystoscopic examination remains the gold standard technique for initial diagnosis of bladder cancer.
- Study 4 found that bladder cancer was an uncommon finding on cystoscopy among patients being evaluated for asymptomatic microscopic hematuria, but it is still an important diagnostic tool.
Rationale for Choosing Cystoscopy
- Cystoscopy allows for direct visualization of the bladder and urethra, which can help identify any abnormalities or lesions that may be causing the hematuria.
- The patient's age and lack of risk factors do not rule out the possibility of bladder cancer or other conditions that may require cystoscopy for diagnosis.
The most appropriate answer is: A Cystoscopy