What are the recommended initial laboratory tests for lymphoma?

Initial Laboratory Tests for Lymphoma

The recommended initial laboratory tests for lymphoma include a complete blood count with differential, comprehensive metabolic panel, lactate dehydrogenase (LDH), beta-2 microglobulin, hepatitis B and C testing, and HIV screening. 1

Core Initial Laboratory Evaluation

Essential Blood Tests

• Complete blood count (CBC) with differential and peripheral blood smear review 1, 2

  • Confirms presence of abnormal cells
  • Evaluates for cytopenias affecting multiple cell lines
  • Provides baseline hematologic parameters

• Comprehensive metabolic panel 1

  • Assesses organ function (liver, kidney)
  • Evaluates electrolyte abnormalities
  • Screens for metabolic derangements

• Lactate dehydrogenase (LDH) 1

  • Critical prognostic marker in most lymphoma subtypes
  • Elevated in aggressive disease and high tumor burden
  • Used in multiple prognostic scoring systems (FLIPI, IPI)

• Beta-2 microglobulin 1, 3, 4

  • Independent prognostic factor for lymphoma outcomes
  • Correlates with tumor burden
  • When combined with LDH, provides powerful risk stratification

Infectious Disease Screening

• Hepatitis B testing (HBsAg, anti-HBs, anti-HBc) 1

  • Essential before initiating anti-CD20 therapy (rituximab)
  • Prevents hepatitis B reactivation during treatment

• Hepatitis C testing 1

  • Particularly important in splenic marginal zone lymphoma
  • Required for high-risk patients

• HIV testing 1

  • HIV-associated lymphomas require specialized management
  • Affects treatment decisions and prognosis

Additional Tests Based on Clinical Context

Immunologic Tests

• Quantitative immunoglobulins 1

  • Particularly relevant in B-cell lymphomas
  • Evaluates for hypogammaglobulinemia or monoclonal gammopathy

• Serum protein electrophoresis 1

  • Detects monoclonal proteins
  • Helps differentiate lymphoma subtypes

Hematologic Tests

• Coagulation studies (PT, PTT, fibrinogen) 1, 2

  • Essential if disseminated intravascular coagulation is suspected
  • Important before invasive procedures

• Reticulocyte count, haptoglobin, direct Coombs test 1

  • If autoimmune hemolytic anemia is suspected
  • Common in certain lymphoma subtypes (CLL/SLL)

Pitfalls and Caveats

1. Don't rely solely on laboratory tests for diagnosis

   • Excisional lymph node biopsy remains the gold standard 1
   • Flow cytometry alone is insufficient for definitive diagnosis 5

2. Interpret laboratory values in clinical context

   • Elevated LDH and beta-2 microglobulin can occur in many conditions
   • Combine with clinical findings and imaging for accurate interpretation

3. Consider timing of laboratory tests

   • Obtain tests before treatment initiation
   • Baseline values are essential for monitoring response and toxicity

4. Don't forget specialized tests for specific lymphoma subtypes

   • Gastric MALT lymphoma: H. pylori testing 1
   • Follicular lymphoma: consider testing for t(14;18) 1
   • DLBCL: consider MYC/BCL2 rearrangements 1

Laboratory Tests by Lymphoma Subtype

For Hodgkin Lymphoma

• Standard panel plus:
  • Erythrocyte sedimentation rate (ESR) 1
  • Albumin (for International Prognostic Score) 1

For Non-Hodgkin Lymphoma

• Standard panel plus:
  • Uric acid (risk of tumor lysis syndrome) 1, 6
  • Flow cytometry on peripheral blood if leukemic presentation 1

Remember that while laboratory tests are essential for diagnosis, staging, and prognostication, they must be integrated with clinical findings, imaging studies, and pathologic examination for comprehensive lymphoma management.