Biopsy of Enlarged Lymph Node is the Best Diagnostic Approach
For suspected lymphoma, excisional (surgical) biopsy of an enlarged lymph node is the definitive diagnostic test and should be performed to establish the diagnosis. 1, 2, 3
Why Biopsy is Superior to Other Options
The other options listed are inappropriate for lymphoma diagnosis:
- CXR (Chest X-ray): Only serves as baseline imaging and cannot establish a tissue diagnosis 4, 3
- CT of pelvis: Useful for staging after diagnosis is confirmed, but cannot diagnose lymphoma without tissue 1, 4
- D-dimer assay: A coagulation marker with no role in lymphoma diagnosis
- Transvaginal ultrasound: Irrelevant for lymphoma evaluation
The Gold Standard: Excisional Lymph Node Biopsy
Surgical (excisional or incisional) biopsy is mandatory because it provides sufficient tissue for comprehensive pathologic analysis including morphology, immunohistochemistry, flow cytometry, and molecular studies required for accurate lymphoma classification. 1, 2, 3
Key advantages of excisional biopsy:
- Provides both fresh frozen and formalin-fixed samples for complete analysis 3
- Allows assessment of lymph node architecture, which is critical for diagnosis 1
- Enables immunophenotypic confirmation with CD45, CD20, CD3, and other markers 1, 3
- Permits molecular studies including MYC and BCL2 rearrangement testing 1
- Must be evaluated by an expert hematopathologist 1, 2
When Core Needle Biopsy May Be Acceptable
Core needle biopsy should only be reserved for patients where surgical biopsy is anatomically impractical or would entail excessive risk. 1, 3
Recent evidence shows core needle biopsy can achieve 87.5% diagnostic yield when PET-CT guided to the most metabolically active areas (median SUVmax 10.7), with 96% sensitivity and 100% specificity 5. However, this remains second-line to excisional biopsy.
Critical Pitfall to Avoid
Fine needle aspiration (FNA) should never be used as the sole basis for lymphoma diagnosis and is explicitly contraindicated. 1, 3 FNA cannot assess lymph node architecture and provides insufficient material for the comprehensive immunophenotypic and molecular analysis required for proper lymphoma classification.
Practical Considerations
- Even small peripheral lymph nodes (≤2 cm) can yield diagnostic tissue and may be preferable to deep invasive procedures when large internal nodes are inaccessible 6
- Surgical biopsy significantly reduces investigation time (1.25 months) compared to starting with needle biopsy first (3 months to final diagnosis) 7
- The specimen must be processed immediately by an experienced pathology institute 3
After Diagnosis is Established
Once tissue diagnosis confirms lymphoma, then proceed with: