What is the appropriate management for white spots in the spleen on ultrasound?

Management of White Spots in the Spleen on Ultrasound

White spots (hyperechoic or hypoechoic lesions) in the spleen on ultrasound require size-based evaluation with contrast-enhanced imaging (CT, MRI, or contrast-enhanced ultrasound) to characterize the lesions and guide management, as conventional ultrasound alone cannot reliably differentiate between benign and malignant etiologies. 1, 2

Initial Diagnostic Approach

Lesion Size Stratification

For lesions <1 cm:

• Follow with serial ultrasound examinations every 3-6 months 3
• Lack of growth over 1-2 years suggests benign etiology and allows return to routine surveillance 3
• If growth is detected, escalate to the algorithm for larger lesions 3

For lesions 1-2 cm:

• Obtain two dynamic contrast studies (CT with IV contrast, contrast-enhanced ultrasound, or MRI with contrast) 3
• CT scan with intravenous contrast is the gold standard with 90-95% sensitivity and specificity 3, 4
• If typical vascular pattern is seen on both studies, proceed with definitive diagnosis 3
• If findings are atypical or discordant between techniques, perform image-guided biopsy 3

For lesions >2 cm:

• Single dynamic imaging study (CT, MRI, or contrast-enhanced ultrasound) is sufficient if characteristic features are present 3
• Biopsy is indicated if vascular profile is not characteristic 3

Key Imaging Characteristics to Assess

Contrast-Enhanced Imaging Patterns

Doppler ultrasound and contrast-enhanced ultrasound (CEUS) are essential for:

• Evaluating splenic vascularization and characterizing focal abnormalities 3, 1
• Differentiating lesions that require further workup from those that can be safely monitored 1
• CEUS is easy to perform, inexpensive, safe, and provides valuable additional information when gray-scale ultrasound is inconclusive 1, 5

Specific Lesion Patterns

Wedge-shaped peripheral lesions suggest splenic infarction:

• Appear as peripheral low-density, wedge-shaped areas on CT 4
• Bland infarcts show clinical and radiographic improvement with appropriate management 4
• Most splenic infarcts should be managed conservatively with supportive care 4

Multiple small hypoechoic lesions (1.5-2.0 mm) in a reticulo-nodular "sponge pattern":

• May represent hyperplastic white pulp in severely immunocompromised patients 6
• Should not be misinterpreted as micro-abscesses without clinical correlation 6

Contrast-enhancing cystic lesions suggest abscess formation:

• Single or multiple contrast-enhancing cystic lesions indicate splenic abscess 4
• Requires differentiation from bland infarction through clinical correlation (ongoing sepsis, recurrent positive blood cultures) 4

Clinical Context Integration

High-Risk Scenarios Requiring Urgent Evaluation

Trauma patients:

• E-FAST is effective and rapid to detect free fluid with sensitivity up to 91% and specificity up to 96% 3
• CT scan with IV contrast is the gold standard in hemodynamically stable or stabilized trauma patients 3
• Serial FAST exams should be performed in response to clinical changes 3

Suspected infection or abscess:

• Monitor for persistent or recurrent fever, ongoing abdominal pain, and bacteremia 4
• Splenic abscess requires splenectomy and appropriate antibiotics if poorly responsive to antibiotics alone 4
• Percutaneous drainage may be considered for poor surgical candidates 4

Hemodynamic instability:

• Bedside FAST has utility in hemodynamically unstable patients to rapidly identify intraperitoneal hemorrhage 3
• Splenic rupture with hemorrhage and hemodynamic instability requires immediate surgical intervention 4

Common Pitfalls to Avoid

• Do not rely on ultrasound alone to characterize splenic lesions, as conventional gray-scale and Doppler ultrasound frequently cannot definitively diagnose focal abnormalities 1, 2
• Do not assume clinical splenomegaly indicates specific pathology, as it is present in only 30% of splenic infarction or abscess cases 4
• Do not dismiss negative biopsy results as conclusive for small lesions; continue surveillance with ultrasound or CT at 3-6 month intervals 3
• Do not delay repeat imaging in patients with moderate/severe lesions, decreasing hematocrit, vascular anomalies, or coagulopathy 4

Follow-Up Strategy

For conservatively managed lesions:

• Repeat CT scanning during admission for moderate/severe lesions 4
• Activity restriction for 4-6 weeks in minor injuries and up to 2-4 months in moderate/severe injuries 4
• Monitor for delayed complications, as delayed rupture can occur within the first 48 hours but more commonly between 4-10 days 4
• Complete healing typically occurs in 12.5 days for minor injuries and 37.2 days for severe injuries 4