What are the next steps if lab work indicates lymphoma?

Laboratory Findings Indicating Lymphoma and Next Steps

When laboratory work suggests lymphoma, the next step should be an excisional/surgical lymph node biopsy for definitive diagnosis, followed by comprehensive staging with PET-CT and appropriate blood tests to determine treatment approach. 1

Diagnostic Workup After Suspicious Lab Findings

Confirmatory Testing

• Excisional lymph node biopsy: Mandatory for accurate diagnosis; fine-needle aspiration is inadequate and should only be used in emergency situations 2, 1
• Expert hematopathology review: Essential for accurate classification according to WHO classification 2, 1
• Immunophenotyping: Should include Pan-B and Pan-T-cell antigens to determine lymphoma subtype 2

Staging Procedures

1. Imaging:

   • PET-CT scan: Recommended for precise staging of nodal and extranodal sites 2, 1
   • CT scan of chest, abdomen, and pelvis with contrast 2
   • Consider MRI of brain if CNS involvement is suspected 2

2. Bone marrow assessment:

   • Bone marrow biopsy with or without aspirate (minimum 20 mm sample) 2, 1
   • May be deferred in select cases of indolent lymphoma with radiographic stage III disease if observation is planned 2

3. Laboratory studies:

   • Complete blood count with differential 2, 1
   • Comprehensive metabolic panel 2
   • Serum LDH (important prognostic marker) 2, 1
   • Hepatitis B testing (HBsAg and HBcAb) before anti-CD20 therapy 2
   • HIV testing 2, 1
   • β2-microglobulin (for prognostic assessment) 2, 1
   • Uric acid level 2, 1

Treatment Approach Based on Lymphoma Type and Stage

Indolent Lymphomas (e.g., Follicular Lymphoma Grades 1-2)

• Stage I-II: Involved-field radiotherapy (30-40 Gy) with curative potential 2
• Stage III-IV:
  • Observation ("watch and wait") for asymptomatic patients 2
  • Initiate treatment for symptomatic disease (B symptoms, hematopoietic impairment, bulky disease, organ compression, or progression) 2, 1
  • Treatment of choice: Rituximab plus chemotherapy (R-CHOP, R-CVP, R-bendamustine) 2, 1

Aggressive Lymphomas (e.g., DLBCL, Follicular Lymphoma Grade 3B)

• All stages: Immediate treatment with immunochemotherapy, typically R-CHOP 1, 3
• Consider CNS prophylaxis for high-risk patients 1

Response Evaluation and Follow-up

Response Assessment

• Perform radiological tests after every 2-3 cycles of therapy and at completion of treatment 2
• PET-CT is recommended for response assessment in FDG-avid lymphomas 2
• Patients with incomplete response should be evaluated for early salvage regimens 2

Follow-up Schedule

• History and physical examination every 3 months for 2 years, every 6 months for 3 additional years, then annually 2
• Blood count at 3,6,12, and 24 months, then as needed 2
• Imaging at 6,12, and 24 months after end of treatment 2
• Monitor for transformation, especially if LDH levels rise, single site grows disproportionately, or new B symptoms develop 2

Common Pitfalls to Avoid

1. Inadequate biopsy: Never rely on fine-needle aspiration for initial diagnosis 2, 1
2. Incomplete staging: Ensure comprehensive staging before treatment decisions 1
3. Missing extranodal disease: Thorough imaging is essential 1
4. Inadequate pathology review: Expert hematopathology review is critical 1
5. Premature treatment: For indolent lymphomas, avoid treating asymptomatic patients without clear indications 2
6. Overlooking hepatitis B status: Test before rituximab to prevent reactivation 2
7. Failure to recognize transformation: Consider in patients with progressive disease, especially with rising LDH 2

By following this systematic approach to diagnosis, staging, and treatment planning, patients with laboratory findings suggestive of lymphoma can receive optimal care with the best chance for favorable outcomes in terms of morbidity, mortality, and quality of life.