From the Guidelines
Episodes of microscopic hematuria during illness accompanied by thrombocytopenia require prompt medical evaluation as they may indicate serious underlying conditions, such as immune thrombocytopenic purpura (ITP), disseminated intravascular coagulation (DIC), hemolytic uremic syndrome (HUS), or certain infections, and should be reported to a healthcare provider immediately for proper diagnosis and management 1.
Key Considerations
- The combination of microscopic hematuria and thrombocytopenia suggests a potential for significant underlying disease, including malignancy, and necessitates a thorough diagnostic evaluation.
- Initial management should include complete blood count monitoring, urinalysis, and possibly renal function tests to assess the severity of the condition and guide further management.
- Treatment depends on the underlying cause but may include platelet transfusions if counts are severely low (below 10,000/μL) or if there is active bleeding, and corticosteroids such as prednisone (1 mg/kg/day) may be prescribed for immune-mediated causes.
- Patients should avoid aspirin and NSAIDs, which can worsen bleeding risk, maintain adequate hydration, and watch for signs of worsening bleeding, including increased blood in urine, nosebleeds, or petechiae.
Diagnostic Approach
- The definition of microscopic hematuria is three or more red blood cells per high power field on microscopic evaluation of urinary sediment from one properly collected, noncontaminated urinalysis with no evidence of infection 1.
- Cystoscopy is the standard diagnostic tool to screen the entire bladder for malignancy in cases of haematuria, and its diagnostic accuracy for detecting bladder cancer in adults presenting with haematuria is a critical consideration in the evaluation of these patients 1.
- A risk classification system for patients with microhematuria, stratified as low-, intermediate-, or high-risk for genitourinary malignancy, can help guide the diagnostic evaluation and management of these patients 1.
Management and Follow-Up
- Patients with suspected urinary tract infection as a cause of microhematuria should have urine cultures performed, preferably before antibiotic therapy, to confirm an infection.
- Patients with a suspected cause of microhematuria, including interstitial cystitis or benign prostatic hyperplasia, should have the appropriate clinical workup before undertaking imaging.
- Follow-up after a negative microhematuria evaluation should be guided by the patient's risk classification and the presence of any underlying conditions that may increase the risk of malignancy or other significant disease.
From the Research
Episodes of Microscopic Hematuria
- Microscopic hematuria is a common finding in adults, defined as the presence of three to five red blood cells per high-power field 2.
- The causes of microscopic hematuria are extensive, but common differential diagnoses include infection, malignancy, and urolithiasis 3.
- Clinical evaluation of patients with microscopic hematuria often involves urine cytology, urine culture, imaging studies, and cystoscopy 3, 2.
Evaluation and Management
- Patients with microscopic hematuria should undergo a thorough history and physical examination to determine potential causes and assess risk factors for malignancy 4.
- If no benign cause for microscopic hematuria is found, the work-up includes laboratory tests to rule out intrinsic renal disease, imaging of the urinary tract, and referral to nephrology and urology subspecialists 4.
- Patients with proteinuria, red cell casts, and elevated serum creatinine levels should be referred promptly to a nephrology subspecialist 2.
Thrombocytopenia and Hematuria
- There is no direct evidence in the provided studies linking thrombocytopenia to episodes of microscopic hematuria during illness.
- However, it is essential to note that hematuria can be a symptom of various underlying conditions, and a thorough evaluation is necessary to determine the cause 5.