Lymphoma versus Reactive Lymphadenopathy

Also written as Lymphoma vs. reactive nodes, Lymph node differential.

Distinguish lymphoma from benign causes of lymph node enlargement using history, exam, basic labs and imaging. Focus on red flags, common tropical infections, and limited tests in low‑resource settings.

Overview

Lymphoma presents as painless, progressive lymphadenopathy, often with systemic symptoms. Reactive nodes are usually tender, transient, and linked to infection or inflammation.

• Painless, firm nodes
• Systemic B symptoms

Key Concepts

Use the WHO/NIH staging for lymphoma and the 2017 WHO classification. In low‑resource settings, rely on clinical features, basic CBC, ESR, and ultrasound.

• CBC: Anemia, leukopenia or leukocytosis; lymphocytosis suggests infection
• ESR/CRP: Elevated in lymphoma but also in infections
• Ultrasound: Node size, cortical thickness, hilum visibility; loss of hilum suggests malignancy

• Painless nodes >2 cm
• Night sweats, fever, weight loss

Clinical Relevance

Early recognition prevents complications like tumor lysis syndrome or opportunistic infections. In East Africa, HIV and TB co‑infection are common confounders.

• HIV rapid test: Positive indicates need for ART and lymphoma risk assessment
• Mantoux/TB PCR: Positive suggests TB lymphadenitis; consider anti‑TB therapy before biopsy

• HIV serology
• TB screening

Exam Pearls

Ask about night sweats, weight loss, recent infections, travel, and drug use. On exam, note node consistency, mobility, and associated skin changes.

• Firm, non‑mobile nodes >2 cm
• No overlying skin changes

Common Mistakes

Assuming all painless nodes are malignant; overlooking TB or HIV; ordering CT when ultrasound is adequate; ignoring B symptoms as red flags.

• Treating reactive nodes with chemotherapy

Management

Treat underlying infection first. For confirmed lymphoma, initiate chemotherapy per local protocols (e.g., CHOP). Provide supportive care: transfusions, infection prophylaxis.

• CHOP regimen: Cyclophosphamide, doxorubicin, vincristine, prednisone; avoids bleomycin due to pulmonary risk
• Growth factors: G‑CSF if neutropenia expected

• Start ART if HIV+
• Use broad‑spectrum antibiotics for TB

Often Confused With

Tuberculous lymphadenitis, sarcoidosis, Kikuchi disease, and metastatic carcinoma.

• TB nodes: matted, caseating
• Sarcoid: bilateral hilar adenopathy

Where Results Can Mislead

Normal ESR does not exclude lymphoma; low CD4 count may mask B symptoms; ultrasound may miss small nodes.

• False‑negative TB PCR in paucibacillary disease

When to Seek Help

Urgent referral if rapid node growth, pain, skin ulceration, or signs of systemic compromise.

• Node >5 cm in 2 weeks
• Fever >39°C persistent
• Weight loss >10% in 3 months

Questions an examiner may ask

• A 28‑year‑old man with a 3‑month history of painless cervical nodes and night sweats – what is the next best step? — Order HIV test, CBC, ESR, and ultrasound before biopsy; consider lymphoma.
• A patient with enlarged nodes and a positive TB PCR – what is the most appropriate management? — Treat TB first, reassess nodes after 2 weeks; if no response, proceed to biopsy.
• Why is bleomycin avoided in patients with chronic lung disease? — It can cause severe pulmonary toxicity.
• What clinical feature distinguishes lymphoma from a reactive node? — Painless, firm, non‑mobile nodes >2 cm with B symptoms.
• When should you refer a patient with lymphadenopathy to oncology? — If nodes are >5 cm, rapidly enlarging, or if biopsy confirms malignancy.
• Why might ESR be normal in lymphoma? — In early disease or in patients with anemia of chronic disease; rely on other findings.
• What is the role of ultrasound in low‑resource settings? — It helps assess node morphology and guides fine‑needle aspiration when biopsy facilities are limited.
• How does HIV infection alter the presentation of lymphoma? — It can mask B symptoms and increase the risk of aggressive subtypes; ART should be started promptly.

When to seek help

• Rapid node growth
• Painful nodes
• Skin ulceration
• Systemic compromise

Quick questions

How do I differentiate lymphoma from TB lymphadenitis clinically?

Lymphoma is painless, firm, and often systemic; TB nodes are matted, may have sinus tracts, and are associated with pulmonary TB signs.

What is the first test I should order when a patient presents with enlarged nodes?

CBC with differential, ESR/CRP, and HIV rapid test; then ultrasound if available.

Why is a biopsy still necessary even if imaging suggests lymphoma?

Imaging cannot confirm histology; biopsy provides definitive diagnosis and guides therapy.