Assessing Lymphadenopathy

Lymphadenopathy may be localised or generalised. The cause of lymphadenopathy is often obvious and is usually a result of a benign infectious cause. Most patients can be diagnosed on the basis of a careful history and physical examination. Generalised adenopathy should always prompt further clinical investigation.¹

• Infection:
  • Regional lymphadenopathy draining primary infection:
    • Viral: adenovirus, mumps, enterovirus, arbovirus, rubella, herpes simplex, infectious mononucleosis
    • Bacterial: staphylococcal and streptococcal infection, tuberculosis, cat scratch disease, brucellosis, plague, filariasis, tularaemia, syphilis, meliodosis, glanders, lymphogranuloma venereum (chlamydia), chancroid, scrub typhus
    • Fungal: blastomycosis, coccidioidomycosis
    • Protozoal: trypanosomiasis, cutaneous leishmaniasis
  • Generalised lymphadenopathy: Many of the infections above although showing a predisposition to certain sites, may also cause generalised lymphadenopathy, particularly secondary syphilis. Others include:
    • Viral, e.g. HIV, CMV, hepatitis B, measles, dengue (arbovirus)
    • Bacterial, e.g. tuberculosis, typhoid fever, septicaemia
    • Protozoal, e.g toxoplasmosis, visceral leishmaniasis
• Primary haematological causes:
  • Leukaemia
  • Hodgkin's and Non-Hodgkins lymphoma (including mycosis fungoides)
  • Myeloproliferative disorders, (including polycythaemia rubra vera)
• Regional lymphadenopathy draining local malignancy
• Other causes include sarcoidosis, systemic lupus erythematosus, rheumatoid arthritis, and drug reactions (particularly if they cause a diffuse rash)

• Localised lymphadenopathy should prompt a search for an adjacent precipitating lesion and an examination of other nodal areas to rule out generalised lymphadenopathy.²
• Lymph nodes greater than 1 cm in diameter are generally considered to be abnormal.¹
• History of malaise and weight loss may be associated with malignancy or certain infections, e.g. HIV, tuberculosis.
• Painful, tender lymph nodes are usually associated with infection.
• Firm or hard, painless nodes are often associated with malignancy.
• Full examination is essential and may reveal associated bruising (e.g. leukaemia) or hepatosplenomegaly (e.g. lymphoma).

See Neck Lumps and Bumps

• Lipomas
• Branchial cleft cysts
• Cystic hygromas
• Salivary glands
• Thyroglossal duct cysts - usually in midline

Will be governed by the history and examination and likely cause of lymphadenopathy. Investigations may not be required in cases of obvious cause and quick resolution with or without treatment.

• Full blood count: white cell count raised in infection or malignancy, blood film for leukaemia
• Acute phase reactants, e.g. ESR and CRP, often raised in infection or malignancy
• Liver function tests: liver infiltration
• Infection:
  • Swabs from primary infection site for culture and sensitivities
  • Viral titres, e.g. Epstein-Barr, HIV
  • Mantoux test: tuberculosis
  • VDRL: syphilis
  • Toxoplasma screen
  • Blood cultures
• Autoantibody screen: SLE, rheumatoid arthritis
• Kveim test: sarcoidosis
• Chest x-ray: sarcoidosis, tuberculosis, primary or secondary malignancy
• CT scan: nodal distribution, staging of lymphoma
• Fine needle aspiration or biopsy of lymph node may be required
• Sentinel node biopsy:
  • The sentinel node is the first node identified or the node with the highest radioactivity count.
  • Sentinel node biopsy can avoid the need for block dissection of lymph nodes. It is often used in the pre-operative assessment of breast cancer and melanoma and may have benefits in other cancers.
  • The sentinel node can be identified either by local injection of blue dye and following its path, or by gamma camera imaging following injection of 99mTc.

The following factors should be considered:

• Careful reappraisal of the history, and full examination is required, determining the size and character of node(s).
• In the absence of obvious infection or an underlying disorder, or any suspicion of malignancy - refer.
• Bilateral anterior cervical nodes up to 2cm are often found in healthy children and adults after recent URTIs.
• Dependent on level of doctor's concern, empirical treatment with antibiotics (usually ant-staph/strep) may be tried, with reevaluation in 2-4 weeks. If unchanged, or larger - refer.
• Some patients, particularly children, remain undiagnosed after biopsy.
• In studies of 9-25yr olds, Size >2cm and an abnormal CXR indicated a greater risk of a sinister cause, and recent ENT symptoms suggested a reduced risk of a sinister cause.
• In another study >40yr olds, >1.5x1.5cm, supraclavicular location, hard consistency, and lack of tenderness or pain showed a positive predictive value of a sinister cause; <40yrs, size <1.0x1.0cm, non-hard consistency, tenderness or pain, showed a negative predictive value of a sinister cause.