What initial blood work is recommended for patients suspected of having lymphoma or leukemia?

Initial Blood Work for Suspected Lymphoma or Leukemia

For patients with suspected lymphoma or leukemia, the initial blood work should include complete blood count (CBC) with differential, comprehensive metabolic panel, lactate dehydrogenase (LDH), beta-2 microglobulin, and hepatitis B and C testing. 1

Core Laboratory Tests

Essential Initial Blood Tests

• Complete Blood Count (CBC) with differential

  • Evaluates for cytopenias affecting multiple cell lines
  • Provides baseline hematologic parameters
  • Identifies presence of abnormal cells
  • Includes manual differential and blood smear with morphology 1

• Comprehensive Metabolic Panel

  • Assesses liver and kidney function
  • Evaluates electrolyte balance 1

• Lactate Dehydrogenase (LDH)

  • Critical prognostic marker in most lymphoma subtypes
  • Elevated in aggressive disease and high tumor burden
  • Used in prognostic scoring systems (FLIPI, IPI) 1

• Beta-2 Microglobulin

  • Independent prognostic factor for lymphoma outcomes
  • Correlates with tumor burden
  • Provides powerful risk stratification when combined with LDH 1

• Hepatitis B and C Testing

  • Essential before potential rituximab or other CD20 monoclonal antibody therapy
  • Prevents reactivation of hepatitis during immunotherapy 1, 2

Additional Tests Based on Clinical Suspicion

For Suspected Lymphoma

• Quantitative Immunoglobulins (IgG, IgA, IgM)
  • Particularly relevant in suspected B-cell lymphomas 1

For Suspected Leukemia

• Reticulocyte Count

  • Helps assess bone marrow function 1

• Flow Cytometry on Peripheral Blood

  • Evaluates lymphocyte subsets
  • Identifies abnormal immunophenotypes
  • Distinguishes between myeloid and lymphoid malignancies 1

Important Considerations

Diagnostic Limitations

• Blood tests alone are insufficient for definitive diagnosis of lymphoma
  • Tissue confirmation through biopsy is always required
  • Surgical excisional lymph node biopsy is the gold standard 1

When to Proceed to Bone Marrow Examination

Bone marrow aspiration and biopsy is essential when:

• Abnormalities in multiple cell lines are present
• Peripheral blood shows abnormal cells
• Leukopenia is severe or persistent without obvious cause 1

Severity-Based Approach

1. Isolated leukopenia with mild weight loss:

   • Begin with CBC with differential and peripheral smear
   • Consider medication review and infectious disease testing
   • Monitor with repeat CBCs before more invasive testing 1

2. Leukopenia with significant weight loss (>10% in 6 months) or other cytopenias:

   • Proceed directly to comprehensive workup including bone marrow examination
   • Include flow cytometry and cytogenetics in initial evaluation 1

3. Severe leukopenia (<1000 WBC/μL) regardless of weight loss:

   • Urgent hematology consultation
   • Immediate bone marrow evaluation
   • Consider prophylactic antibiotics if neutropenic 1

Prognostic Markers

• FLIPI parameters include:

  • Hemoglobin level (<12 g/dL is adverse factor)
  • LDH (elevated is adverse factor)
  • Age, stage, and number of nodal sites 1

• IPI parameters include:

  • LDH (elevated is adverse factor)
  • Age, stage, performance status, and extranodal sites 1

Common Pitfalls to Avoid

• Relying solely on blood tests for lymphoma diagnosis

  • Always obtain tissue confirmation through biopsy 1

• Using fine-needle aspiration for initial lymphoma diagnosis

  • Generally inappropriate; excisional biopsy preferred 1

• Delaying bone marrow examination in patients with severe or persistent cytopenias

  • Could delay diagnosis and appropriate treatment 1

• Overlooking hepatitis testing

  • Critical before potential rituximab therapy to prevent hepatitis reactivation 1, 2

• Failing to monitor CBC regularly in high-risk patients

  • For high-risk MDS/AML predisposition: every 3-4 months initially
  • Extend to 6-12 months if stable 1