About This Page
This is a clinician-written, evidence-based guide aligned to the MCC Examination Objectives. It is structured by clinical presentation — the way the MCCQE tests and the way patients actually present. Management reflects current Canadian guidelines (CMA, CFPC, CPS). Always cross-reference with institutional protocols and clinical judgment.
The Bottom Line
- Palpable lymph nodes are usually reactive, but the task is to distinguish benign localized infection from lymphoma, metastatic cancer, tuberculosis, HIV, autoimmune disease, drug causes and biopsy-requiring disease.
- Start with acuity and stability before narrowing the differential.
- Use CBC with differential, smear, coagulation studies and targeted tests according to the presentation pattern.
- Escalate urgently for abnormal smear, systemic red flags, major bleeding, sepsis, thrombosis, neurologic symptoms or suspected malignancy.
- Management is cause-directed and should follow Canadian transfusion, thrombosis and cancer diagnostic pathway principles.
Approach to the Presentation
Lymphadenopathy is approached as a clinical presentation rather than as a single diagnosis. Begin by assessing stability, bleeding or thrombosis risk, infection/sepsis features, medication exposures, pregnancy status where relevant, and systemic red flags. Then use the pattern of the abnormality — CBC lineage, smear morphology, coagulation pathway, node distribution, spleen size, or VTE pre-test probability — to select focused investigations. For MCCQE1, the safest answer is usually the one that identifies must-not-miss disease while avoiding reflex treatment of an isolated laboratory value.
Differential Diagnosis
| diagnosis | likelihood | key features | distinguishing test |
|---|---|---|---|
| Lymphoma (Hodgkin or non-Hodgkin) | must-not-miss | Painless firm rubbery nodes, B symptoms, pruritus, alcohol-induced node pain, mediastinal symptoms, splenomegaly. | Excisional lymph node biopsy with histology, immunophenotyping and staging imaging. |
| Metastatic carcinoma | must-not-miss | Hard fixed node, supraclavicular node, older patient, smoking/alcohol, mucosal lesion, breast mass, melanoma, weight loss. | Imaging of drainage territory plus FNA/core/excisional biopsy depending on suspected source. |
| Tuberculosis or atypical mycobacterial infection | must-not-miss | Chronic cervical nodes, constitutional symptoms, TB exposure, immigration/travel, immunosuppression; matted nodes. | TB testing, chest imaging, AFB culture/PCR from tissue or aspirate. |
| Acute leukemia | must-not-miss | Nodes with fever, pallor, bruising, infections, bone pain, hepatosplenomegaly. | CBC with differential and smear showing blasts; bone marrow biopsy. |
| Reactive viral lymphadenopathy | common | Recent URTI, tender mobile nodes, fever, pharyngitis, fatigue; often self-limited. | Clinical; CBC may show lymphocytosis; resolves over weeks. |
| EBV/CMV infectious mononucleosis | common | Fever, sore throat, posterior cervical nodes, fatigue, splenomegaly; amoxicillin rash in EBV. | Heterophile antibody or EBV serology; atypical lymphocytes. |
| Bacterial lymphadenitis | common | Tender warm node, overlying erythema, fever, local skin/dental/ENT source. | Clinical; ultrasound if abscess suspected; culture if drained. |
| HIV seroconversion or chronic HIV | less common | Generalized lymphadenopathy, fever, rash, sore throat, mucosal ulcers, risk exposure. | HIV Ag/Ab test with follow-up RNA if acute infection suspected. |
| Autoimmune disease | less common | Generalized nodes with rash, arthritis, photosensitivity, pulmonary symptoms or erythema nodosum. | Targeted autoimmune testing and chest imaging based on syndrome. |
| Cat-scratch disease | less common | Regional tender nodes after cat scratch/bite, often axillary or epitrochlear, low-grade fever. | Clinical plus Bartonella serology if uncertain or severe. |
Red Flags & Key History
Symptoms
Drenching night sweats, unexplained fever or >10% weight loss — lymphoma B symptoms
Progressive enlargement, persistence beyond 4-6 weeks or recurrence after antibiotics
Smoking, alcohol use, dysphagia, hoarseness, oral ulcer, breast mass or melanoma lesion
TB exposure, immigration/travel from high-prevalence region, chronic cough or immunosuppression
Fever, bruising, infections, bone pain or fatigue — leukemia clues
Recent URTI, sore throat, dental infection or skin lesion in drainage area
Signs
Supraclavicular lymphadenopathy — high malignancy risk
Hard, fixed, matted, non-tender or >2 cm node
Generalized lymphadenopathy with hepatosplenomegaly
Mediastinal compression symptoms: dyspnea, facial swelling or venous distension
Tender mobile node with local erythema and clear drainage source
Approach to Investigation
First-line
Focused examination of drainage areaInspect scalp, mouth, teeth, oropharynx, thyroid, breasts, skin, genital region, lower limbs and suspicious lesions.
CBC with differential and smearAssess lymphocytosis, atypical lymphocytes, blasts, anaemia, thrombocytopenia or neutropenia.
CRP/ESR, liver tests, LDHSupport infection/inflammation, EBV/hepatitis involvement and lymphoma risk context.
Targeted infectious testingEBV/CMV, HIV, TB, syphilis, toxoplasmosis, Bartonella or throat culture depending on presentation.
Second-line
Ultrasound of superficial node basinAssesses size, morphology, vascularity, necrosis and guides biopsy.
Chest X-ray or CT imagingIf systemic symptoms, mediastinal symptoms, supraclavicular node, suspected lymphoma/TB/metastatic disease.
Age-appropriate cancer screening and site-directed imagingBreast imaging, ENT evaluation, skin assessment and abdominal/pelvic imaging as indicated.
Specialist
Excisional lymph node biopsyPreferred when lymphoma suspected because architecture and immunophenotyping are required.
FNA/core biopsyUseful for suspected metastatic carcinoma; negative FNA does not exclude lymphoma if suspicion remains high.
Management Principles
MCC Lymphadenopathy objective + Cancer Care Ontario cervical lymphadenopathy pathway principles1
Low-risk localized nodes
- Treat a clear benign infection and arrange follow-up to confirm resolution.
- Observation is reasonable for small mobile tender nodes after viral illness when no red flags are present.
- Avoid repeated empiric antibiotics when there is no bacterial source or the node persists/progresses.
2
High-risk nodes or systemic symptoms
- Arrange urgent imaging and tissue diagnosis rather than prolonged observation.
- Refer urgently for supraclavicular nodes, hard/fixed nodes, B symptoms, generalized nodes, hepatosplenomegaly or abnormal CBC/smear.
- If lymphoma is suspected, prioritize excisional biopsy and avoid corticosteroids before biopsy unless specialist-directed emergency exists.
3
Condition-specific management
- Bacterial lymphadenitis: antibiotics targeting likely organisms and drainage if abscess.
- EBV: supportive care; avoid contact sports if splenomegaly.
- TB, HIV, malignancy or autoimmune disease: targeted specialist referral and definitive therapy.
Complications & Pitfalls
- Do not biopsy the easiest node blindly: choose the most abnormal and informative node.
- Do not give steroids before lymphoma biopsy: they can obscure histology.
- Supraclavicular nodes are malignant until proven otherwise.
- Do not overuse antibiotics: persistent unexplained nodes need a diagnosis.
- Always examine drainage territory.
MCCQE1 Exam Tips
- 1Red flags should push toward tissue diagnosis.
- 2Posterior cervical nodes + sore throat + fatigue + splenomegaly = EBV; avoid contact sports.
- 3Painless rubbery nodes + B symptoms = lymphoma until proven otherwise; next step is excisional biopsy.
- 4Hard fixed supraclavicular node in an older smoker = metastatic malignancy pattern.
- 5Generalized lymphadenopathy has a systemic differential: HIV, EBV/CMV, lymphoma/leukemia, autoimmune disease, medications.
- 6Blasts or pancytopenia with nodes = urgent haematology.
practicetest your knowledge on lymphadenopathyApply what you've learnt with MCCQE1-style questions from the iatroX Q-Bank — haematologic & oncologic and beyond.
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