What is the approach to evaluate for lymphoma?

Comprehensive Approach to Lymphoma Evaluation

The definitive approach to evaluate for lymphoma requires an excisional or incisional biopsy of an abnormal lymph node for pathologic examination, followed by PET-CT imaging for staging in FDG-avid lymphomas. 1

Initial Diagnostic Evaluation

Clinical Assessment

• Obtain a comprehensive history focusing on:

  • Constitutional symptoms: fevers >101°F (38.3°C), drenching night sweats, unexplained weight loss >10% over 6 months 1
  • Specific symptoms: fatigue, pruritus, alcohol-induced pain (especially in Hodgkin lymphoma) 1
  • History of malignancy 1

• Physical examination should include:

  • Measurement of all accessible lymph node groups 1
  • Assessment of spleen and liver size (in centimeters below costal margin) 1
  • Note: Physical examination alone has limitations in accurately assessing lymph node size, particularly in supraclavicular and axillary regions 2

Laboratory Studies

• Complete necessary laboratory tests for:
  • Determination of prognostic indices specific to lymphoma subtypes 1
  • Assessment of comorbidities 1

Pathologic Diagnosis

Tissue Acquisition

• An excisional or incisional biopsy is strongly preferred for initial diagnosis 1
• Fine-needle aspiration is inadequate for initial diagnosis 1
• Core-needle biopsy may be considered only when excisional biopsy is not possible 1
• Non-diagnostic samples must be followed by proper excisional biopsy 1

Pathologic Analysis

• Diagnosis requires comprehensive evaluation by an experienced lymphoma pathologist including:
  • Morphology 1
  • Immunohistochemistry 1
  • Flow cytometry 1
  • Molecular studies (where appropriate) for accurate lymphoma categorization 1

Imaging and Staging

Imaging Selection

• PET-CT is the gold standard for staging FDG-avid nodal lymphomas 1
• CT scan is preferred for non-FDG-avid lymphomas (chronic lymphocytic leukemia/small lymphocytic lymphoma, lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia, mycosis fungoides, and marginal zone NHLs) 1
• Chest x-ray is no longer required in lymphoma staging 1

Site-Specific Assessment

• Lymph nodes: PET-CT for FDG-avid histologies; CT for non-avid disease 1
• Spleen/Liver: PET-CT for FDG-avid histologies; CT for non-avid disease 1
• CNS: CT, MRI, and CSF assessment when clinically indicated 1
• Bone marrow: PET-CT is adequate for determination of involvement in most cases 1
• Other sites (skin, lung, GI tract): PET-CT and biopsy as needed 1

Staging Classification

• Ann Arbor staging system remains the foundation for classification 1
• The Lugano classification incorporates modern imaging findings into staging 1, 3
• Staging should include assessment of:
  • Disease location and extent 1
  • Presence of bulky disease 1
  • Presence of B symptoms (fever, weight loss, night sweats) 1

Common Pitfalls to Avoid

• Relying solely on physical examination for lymph node assessment, which has significant limitations, especially in supraclavicular and axillary regions 2
• Using fine-needle aspiration as the sole diagnostic procedure 1
• Failing to obtain adequate tissue for comprehensive pathologic evaluation 1
• Not performing baseline PET-CT before therapy in FDG-avid lymphomas, which compromises accurate response assessment 1
• Performing routine chest x-rays, which are less accurate than CT 1

Special Considerations

• For suspected transformation of indolent lymphoma, PET-CT can help identify the most metabolically active site for biopsy 1
• Biopsy confirmation may be needed for extralymphatic sites identified on imaging 1
• In cases of persistent lymphadenopathy (>1 month), invasive diagnostic procedures are indicated to rule out malignancy 4