What are the diagnostic tests and treatment options for a patient with suspected lymphoma?

Diagnostic Tests and Treatment Options for Suspected Lymphoma

The definitive diagnosis of lymphoma requires a surgical excisional lymph node biopsy or adequate tissue specimen, followed by comprehensive staging with imaging studies including PET-CT, and risk-stratified treatment with chemotherapy regimens specific to the lymphoma subtype. 1

Diagnostic Workup

Initial Tissue Diagnosis

• Excisional lymph node biopsy is the gold standard for diagnosis, providing sufficient material for fresh frozen and formalin-fixed samples 1
• Core biopsies should only be used when surgical biopsy is impractical or too risky 1
• Fine-needle aspirates alone are insufficient for diagnosis 1
• Immunophenotyping is mandatory to confirm diagnosis and determine lymphoma subtype 1

Essential Laboratory Tests

• Complete blood count with differential to evaluate bone marrow involvement and cytopenias 2
• Comprehensive metabolic panel including liver enzymes and albumin 1
• Lactate dehydrogenase (LDH) - critical prognostic marker and component of the International Prognostic Index 2, 1
• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) 1
• Hepatitis B, C, and HIV screening (compulsory before treatment) 1, 2
• Coagulation studies (prothrombin time, partial thromboplastin time) 2
• Uric acid levels to assess risk of tumor lysis syndrome 2

Imaging Studies

• Chest X-ray (mandatory) 1
• Contrast-enhanced CT scan of neck, chest, and abdomen (mandatory) 1
• Whole-body PET scan - gold standard for staging and response assessment 1
• MRI for suspected CNS involvement 1

Additional Diagnostic Tests

• Bone marrow biopsy - no longer indicated if PET-CT is performed for Hodgkin lymphoma, but still required for most non-Hodgkin lymphomas 1, 2
• Lumbar puncture for high-risk patients to rule out CNS involvement 1
• Flow cytometry for determining lymphoma subtype and clonality 2
• Assessment of MYC and BCL2 rearrangement using interphase FISH for DLBCL 1

Pre-treatment Evaluations

• Cardiac function assessment (ECG, echocardiography) - essential before anthracycline-based regimens 1
• Pulmonary function tests 1
• Reproductive counseling for patients of reproductive age 1

Staging and Risk Assessment

• Ann Arbor classification system is used for staging 1
• International Prognostic Index (IPI) and age-adjusted IPI (aa-IPI) for risk stratification in non-Hodgkin lymphoma 1
• B symptoms assessment (fever, night sweats, weight loss >10% over 6 months) 1
• After staging, Hodgkin lymphoma patients are allocated to limited, intermediate, or advanced stage categories 1

Treatment Options

Hodgkin Lymphoma Treatment

• Limited-stage disease: Combined-modality treatment with 2-3 cycles of ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) followed by involved-site radiotherapy 1
• Dosing for Hodgkin's Disease: Bleomycin 0.25-0.50 units/kg (10-20 units/m²) given intravenously, intramuscularly, or subcutaneously weekly or twice weekly 3
• Caution with bleomycin: Total doses over 400 units should be given with great caution due to dose-related pulmonary toxicity 3

Diffuse Large B-Cell Lymphoma (DLBCL) Treatment

• Standard treatment: R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) given every 21 days 1, 4
• Young low-risk patients (aa-IPI=0): Six cycles of R-CHOP 1
• Young low-intermediate risk patients (aa-IPI=1) or with bulky disease: Six cycles of R-CHOP with radiotherapy to sites of previous bulky disease or intensified regimen R-ACVBP 1
• Young high and high-intermediate risk patients (aa-IPI≥2): Six to eight cycles of R-CHOP 1
• Cyclophosphamide dosing: 40-50 mg/kg intravenously in divided doses over 2-5 days when used as single agent; dose adjustments needed when used in combination regimens 5

Special Considerations

• Tumor lysis precautions for patients with high tumor burden 1
• Growth factor support recommended for patients >60 years or at high risk of febrile neutropenia 1
• CNS prophylaxis for high-risk patients 1
• Dose reductions due to hematological toxicity should be avoided when possible 1

Follow-up and Monitoring

• Regular surveillance for complications and relapse after achieving remission 4
• Age-appropriate cancer screenings as recommended by USPSTF 4
• Vaccination: 13-valent pneumococcal conjugate vaccine followed by 23-valent pneumococcal polysaccharide vaccine at least eight weeks later 4

Common Pitfalls to Avoid

• Relying on fine-needle aspirates alone for diagnosis 1
• Omitting hepatitis and HIV screening before treatment 1
• Failing to offer fertility preservation options to patients of reproductive age 1
• Exceeding 400 units total dose of bleomycin due to risk of pulmonary toxicity 3
• Inappropriate dose reductions that may compromise treatment efficacy 1
• Neglecting to provide adequate hydration during cyclophosphamide administration to reduce risk of urinary tract toxicity 5