To whom should a patient with mediastinal lymphadenopathy be referred when lymphoma or malignancy is suspected and an interventional radiology (IR) biopsy is pending?

Referral Pathway for Mediastinal Lymphadenopathy with Suspected Lymphoma or Malignancy

A patient with mediastinal lymphadenopathy where lymphoma or malignancy is suspected should be referred to a thoracic oncologist or pulmonologist with expertise in interventional pulmonology for further management, even while the IR biopsy is pending.

Initial Assessment and Referral Decision-Making

Determining the Appropriate Specialist:

• Thoracic oncologist/pulmonologist with interventional expertise should be the primary referral for:

  • Mediastinal lymphadenopathy with suspected lung cancer or lymphoma
  • Cases requiring comprehensive staging and treatment planning
  • Patients needing additional diagnostic procedures beyond the pending IR biopsy 1

• Hematologist-oncologist should be consulted when:

  • Strong clinical suspicion of lymphoma based on imaging characteristics
  • "B" symptoms present (fever, night sweats, weight loss)
  • Previous history of lymphoma 1

Timing of Referral:

The referral should occur concurrently with the pending IR biopsy, not after results, because:

1. Specialist input may guide additional tissue sampling needs
2. Early multidisciplinary planning improves outcomes
3. Appropriate staging workup can be initiated promptly 1, 2

Diagnostic Considerations

Biopsy Approach:

While IR biopsy is already pending, it's important to understand that:

• Core needle biopsy is often adequate for diagnosis of carcinoma (sensitivity 98%) 3
• Excisional lymph node biopsy is generally preferred for suspected lymphoma 1
• EBUS-TBNA has emerged as a cornerstone diagnostic technique with high sensitivity (76-93%) and specificity (96-100%) for mediastinal lymph node assessment 1, 4

Diagnostic Yield Considerations:

• For lymphoma diagnosis, EBUS-TBNA has a pooled diagnostic accuracy of 68.7% 1
• Higher diagnostic yield for relapsed lymphoma compared to de novo lymphoma 1
• Excisional biopsy may still be needed for definitive lymphoma subtyping 1, 5

Clinical Pathway Algorithm

1. Immediate referral to thoracic oncologist/pulmonologist while IR biopsy is pending

2. Concurrent imaging assessment:

   • PET/CT is preferred for suspected lymphoma or FDG-avid malignancies 2
   • Contrast-enhanced CT for comprehensive staging 1

3. Post-biopsy pathway:

   • If biopsy confirms carcinoma: continue with thoracic oncology management
   • If biopsy confirms lymphoma: add hematology-oncology to the team
   • If biopsy is non-diagnostic: specialist will determine need for additional procedures (mediastinoscopy, EBUS, etc.) 1

Common Pitfalls to Avoid

• Waiting for biopsy results before referral: This delays comprehensive care planning
• Inadequate tissue sampling: Ensure the IR team is aware of the need for sufficient tissue for molecular testing and flow cytometry if lymphoma is suspected 1
• Missing rare diagnoses: Be aware that mediastinal lymphadenopathy can represent tuberculosis, sarcoidosis, or other non-malignant conditions 4, 6
• Overlooking ambulatory options: Many diagnostic procedures for mediastinal lesions can be safely performed on an outpatient basis 7

Key Considerations for General Internists

• Size matters: Lymph nodes >15mm in short axis are more likely to be pathologic 1
• Location matters: Massive lymphadenopathy adjacent to the hilum is particularly characteristic of small cell lung cancer 1
• Symptoms matter: Classic "B" symptoms strongly suggest lymphoma and should prompt expedited referral 1
• Tissue matters: Communicate with the IR team about the need for adequate tissue for all potential diagnostic tests 1

By following this approach, general internists can ensure patients with suspected malignant mediastinal lymphadenopathy receive timely, appropriate specialist care while diagnostic evaluation is ongoing.