What is the initial workup for suspected lymphoma?

Initial Workup for Suspected Lymphoma

The initial workup for suspected lymphoma should include a surgical specimen/excisional lymph node biopsy, comprehensive laboratory studies, and appropriate imaging based on suspected lymphoma type. 1

Biopsy and Pathological Diagnosis

• An excisional lymph node biopsy is mandatory for accurate diagnosis and should be the first step in lymphoma workup 1
• Core biopsies should only be performed when lymph nodes are not easily accessible (e.g., retroperitoneal disease) 1
• Fine needle aspirations are inappropriate for reliable lymphoma diagnosis 1
• Fresh frozen tissue should be stored when possible to allow for additional molecular analyses 1
• The histological report should provide diagnosis according to the World Health Organization (WHO) classification 1

Laboratory Studies

• Complete blood count with platelets and differential 1
• Blood chemistry profile including:
  • Lactate dehydrogenase (LDH) 1
  • Uric acid 1
  • Renal function tests 1
  • Liver function tests 1
  • β2-microglobulin (especially for follicular lymphoma) 1
• Disseminated intravascular coagulation (DIC) panel including:
  • D-dimer 1
  • Fibrinogen 1
  • Prothrombin time (PT) 1
  • Partial thromboplastin time (PTT) 1
• Tumor lysis syndrome panel including:
  • Serum LDH 1, 2
  • Uric acid 1
  • Potassium 1
  • Phosphates 1
  • Calcium 1
• Screening tests for HIV and hepatitis B and C 1

Imaging Studies

• CT scan of neck, thorax, abdomen, and pelvis 1
• PET-CT is not mandatory for all lymphoma types but may be useful to:
  • Confirm localized stage I/II disease 1
  • Identify areas with high standardized uptake values suspected of disease transformation 1
  • Serve as baseline for response assessment 1
• For patients with T-cell lymphoma, chest CT scans are particularly important 1
• For suspected lymphoblastic lymphoma, whole body PET/CT scan is recommended 1

Bone Marrow Assessment

• Bone marrow aspirate and biopsy should be performed in all cases 1
• This helps determine disease extent and involvement of the bone marrow 1

Additional Evaluations Based on Lymphoma Type

• For male patients with suspected lymphoma:

  • Evaluation for testicular involvement 1
  • Testicular involvement is especially common in T-cell ALL 1
  • Scrotal ultrasound as indicated 1

• For patients with suspected CNS involvement:

  • Lumbar puncture for cerebrospinal fluid analysis 1
  • CT/MRI scan of the head with contrast if neurologic symptoms are present 1

• For patients with suspected gastrointestinal involvement:

  • Gastrointestinal endoscopy may be recommended, especially in limited stage I/II disease 1

Risk Assessment and Staging

• Staging should be performed according to the Ann Arbor classification system 1
• For follicular lymphoma, the Follicular Lymphoma-specific International Prognostic Index (FLIPI) should be determined 1
• For mantle cell lymphoma, assessment of Ki-67 as a histomorphological risk factor is recommended 1

Common Pitfalls to Avoid

• Relying on fine needle aspiration or core biopsies alone for diagnosis, which can miss the heterogeneity of lymphoma 1
• Starting treatment before obtaining adequate tissue for diagnosis 1
• Administering corticosteroids before biopsy, which can mask histologic diagnosis of lymphoma 3
• Overlooking the need for specialized immunohistochemistry (e.g., cyclin D1 for mantle cell lymphoma) 1
• Assuming that routine blood tests alone can detect lymphoma relapse (they have poor sensitivity and positive predictive value) 4

By following this comprehensive diagnostic approach, clinicians can ensure accurate diagnosis and staging of lymphoma, which is essential for determining appropriate treatment strategies and improving patient outcomes.