Can a lymphoma in the chest wall appear on ultrasound as swelling?

Lymphoma in the Chest Wall: Ultrasound Appearance

Yes, lymphoma in the chest wall can appear as swelling on ultrasound, typically presenting as hypoechoic masses with characteristic patterns that may help distinguish it from other conditions, though definitive diagnosis requires tissue sampling.

Ultrasound Characteristics of Lymphoma in the Chest Wall

Lymphoma involving the chest wall can be visualized on ultrasound with several characteristic features:

Common Ultrasound Findings

• Hypoechoic appearance: Lymphomatous involvement typically appears as hypoechoic (dark) areas on ultrasound 1
• Homogeneous echogenicity: Often presents with homogeneous internal echo pattern (seen in approximately 52% of cases) 2
• Mass-like swelling: Appears as soft tissue swelling or mass in the chest wall 3, 4
• Specific patterns: Two main patterns may be observed:
  • Linear echogenic strands pattern: Marked hypoechoic areas with interspersed linear echogenic strands
  • Segmental pattern: Multiple, relatively large hypoechoic segments 5

Lymph Node Involvement

• Round-shaped lymph nodes are more likely to be malignant than triangular or draping lymph nodes 1
• Distinct margins, heterogeneous echogenicity, and central necrosis are independently predictive of malignancy 1
• Increased vascularity (assessed by power/color Doppler) with multiple vessels (>4) suggests malignancy with sensitivity of 87.7% and specificity of 69.6% 1

Diagnostic Considerations

While ultrasound can identify suspicious features, it has important limitations:

Limitations of Ultrasound

• Transthoracic ultrasound can only evaluate masses accessible to the sonographic window 1
• Ultrasound alone cannot provide definitive diagnosis of lymphoma 1
• The tissue characterization capability of ultrasound is inferior to MRI but comparable to CT 1

Recommended Diagnostic Approach

1. Initial imaging: If chest wall swelling is detected on ultrasound with suspicious features, cross-sectional imaging is recommended
2. Cross-sectional imaging: MRI is superior to CT for detection of invasion across tissue planes, including chest wall involvement, due to higher soft tissue contrast 1
3. Tissue sampling: Image-guided biopsy is essential for definitive diagnosis
   • Core biopsy is more effective than fine-needle aspiration, especially for lymphoma 1
   • CT-guided or ultrasound-guided biopsy can be performed depending on lesion accessibility 1

Clinical Pearls and Pitfalls

Important Considerations

• Lymphoma can present as an isolated chest wall mass without significant mediastinal lymphadenopathy, as demonstrated in case reports 3, 4
• Chest wall lymphoma may develop at sites of previous trauma or chronic inflammation 3
• Ultrasonographic predictors of malignancy in lymph nodes are not reliable enough to forgo biopsy 1

Differential Diagnosis

When evaluating chest wall swelling on ultrasound, consider:

• Primary chest wall tumors (benign or malignant)
• Metastatic disease
• Inflammatory conditions
• Post-traumatic changes

Conclusion

While ultrasound can identify suspicious features of lymphoma in the chest wall as hypoechoic swelling or masses, definitive diagnosis requires tissue sampling. The ultrasonographic appearance can guide clinical suspicion, but should not replace appropriate cross-sectional imaging and biopsy for diagnosis and staging.