What is the process for staging B cell lymphoma?

Staging Process for B-cell Lymphoma

FDG-PET/CT scan is the gold standard for staging B-cell lymphoma, combined with bone marrow biopsy, comprehensive laboratory testing, and clinical assessment to determine disease extent and prognosis. 1

Initial Clinical Assessment

• Complete history with specific focus on:

  • B symptoms (fever, night sweats, weight loss)
  • Organ-specific signs
  • Performance status evaluation

• Thorough physical examination to document:

  • All involved lymph node regions
  • Extranodal sites of disease
  • Bulky disease (≥10 cm)

Laboratory Investigations

Essential Blood Tests:

• Complete blood count with differential
• Comprehensive blood chemistry including:
  • Lactate dehydrogenase (LDH) - critical prognostic marker
  • Uric acid (to assess risk of tumor lysis syndrome)
  • Protein electrophoresis
  • Renal and liver function tests

Serological Testing:

• HIV screening
• Hepatitis B and C screening (essential before rituximab therapy)
• In European areas with endemic Borrelia burgdorferi: serology and PCR for B. burgdorferi (particularly for PCMZL cases) 1

Imaging Studies

Primary Imaging:

• FDG-PET/CT scan - current gold standard for staging 1
  • More accurate than contrast-enhanced CT alone
  • Increased sensitivity for both nodal and extranodal sites
  • Essential for baseline assessment and subsequent response evaluation

Additional Imaging:

• Contrast-enhanced CT may be required for:

  • Better delineation of lymphadenopathy from bowel
  • Detection of vascular compression/thrombosis
  • Radiation planning
  • More accurate measurement of nodal sites for clinical trials

• MRI for suspected CNS involvement 1

Bone Marrow Assessment

• Bone marrow biopsy and aspirate:
  • Required in primary cutaneous large B-cell lymphoma (PCLBCL)
  • Essential in follicular lymphoma presenting in skin (11% bone marrow involvement rate) 1
  • May be detected by focal bone marrow FDG uptake on PET/CT
  • Low-volume involvement (<10-20%) may be missed by PET/CT imaging 1

Pathological Assessment

Tissue Sampling:

• Excisional lymph node or extranodal tissue biopsy preferred
• Core biopsies acceptable only in emergency situations 1

Immunohistochemistry:

• Minimal panel: CD45, CD20, CD3 1
• Extended panel for subtyping:
  • CD10, BCL-2, BCL-6, MUM-1, FOXP1 for DLBCL subtyping
  • CD5, cyclin D1 to exclude mantle cell lymphoma
  • Ki-67 to determine proliferative fraction 1

Staging Classification and Risk Assessment

Ann Arbor Staging System 1:

• Stage I: Single lymphatic region or localized extralymphatic site
• Stage II: Two or more lymphatic regions on same side of diaphragm
• Stage III: Lymphatic regions on both sides of diaphragm
• Stage IV: Diffuse or disseminated extralymphatic organ involvement

Prognostic Assessment:

• International Prognostic Index (IPI) calculation
• Age-adjusted IPI (aa-IPI) for treatment stratification 1

Special Considerations

• CNS risk assessment: Consider diagnostic spinal tap in high-risk patients 1
• Cardiac function assessment (LVEF) before anthracycline-based therapy
• Molecular testing for specific translocations (e.g., t(14;18)) in suspected follicular lymphoma 1

Common Pitfalls to Avoid

1. Inadequate tissue sampling: Core biopsies may miss architectural features - excisional biopsy preferred when possible
2. Omitting bone marrow biopsy: Particularly important in follicular lymphoma with cutaneous presentation
3. Relying solely on CT without PET: May miss extranodal disease and lead to understaging
4. Neglecting hepatitis screening: Critical before rituximab therapy to prevent reactivation
5. Overlooking CNS risk assessment: High-risk patients need CSF evaluation

By following this comprehensive staging approach, clinicians can accurately determine disease extent, assess prognosis, and guide appropriate treatment selection to optimize outcomes for patients with B-cell lymphoma.