Lymphadenopathy in Children
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Direct answer
Lymphadenopathy in children is enlargement of lymph nodes, and most cases are reactive to a nearby infection. The key task is separating benign reactive nodes, which are tender, soft and mobile and settle within two to four weeks, from malignant nodes, which are hard, painless, fixed and persistent, often with fever, weight loss or night sweats. Supraclavicular nodes and non-regressing nodes warrant excision biopsy rather than repeated observation.
What you must remember
- Normal versus enlarged: cervical, axillary and inguinal nodes under about 1 cm are commonly normal, while nodes above 2 cm need prompt evaluation.
- Reactive pattern: tender, soft, mobile nodes after a sore throat, skin infection or viral illness, with Epstein-Barr virus and streptococci as common triggers.
- Malignant red flags: hard, rubbery, painless or fixed nodes, supraclavicular site, size above 2 cm, and persistence beyond two to four weeks.
- B symptoms: unexplained persistent fever, drenching night sweats and unexplained weight loss raise suspicion of lymphoma.
- Commonest malignancies: Hodgkin and non-Hodgkin lymphoma and acute leukaemia, which may present with nodes alone or with cytopenias.
- Biopsy of choice: excision or core biopsy, because lymphoma needs nodal architecture for histology and immunophenotyping; fine-needle aspiration alone is usually inadequate.
A graded pathway from reactive node to tissue diagnosis
A child with a single node is usually reviewed before anything invasive is done. The pathway below moves forward only when a red flag or a failure to settle appears.
- Targeted history: ask about duration, preceding sore throat or skin infection, cat contact, travel, weight loss, night sweats and drug history, since phenytoin can cause a pseudolymphoma picture.
- Nodal examination: record site, size, consistency, tenderness, mobility and overlying skin, and look for hepatosplenomegaly.
- First-line tests: complete blood count with peripheral smear, ESR, and serology for Epstein-Barr virus, cytomegalovirus, toxoplasma or HIV when suggested; Mantoux or interferon-gamma release assay where tuberculosis is possible.
- Imaging: ultrasonography to characterise the node and chest X-ray to look for mediastinal masses.
- Time-limited observation: reassess after two to four weeks of treating a suspected bacterial infection, since regression supports a reactive cause.
- Tissue diagnosis: excision biopsy for persistent, suspicious or systemic nodes, with histopathology and flow cytometry; aspiration cytology with culture may suffice when tuberculosis is suspected.
Where the exam tries to catch you
Vignettes on lymphadenopathy reward the ability to reject a tempting diagnosis.
- Trap: calling every neck node malignant Correct: small, tender, mobile nodes in a child with a recent sore throat are reactive and need review, not biopsy.
- Trap: choosing fine-needle aspiration for suspected lymphoma Correct: excision or core biopsy preserves the architecture needed for subtyping.
- Trap: dismissing a supraclavicular node Correct: this site is rarely reactive, so biopsy is indicated early.
- Trap: accepting fever with nodes as infection alone Correct: phenytoin, serum sickness and toxoplasmosis can mimic lymphoma, so drug history and serology matter.
Frequently asked questions
Which lymph node size is abnormal in a child?
Nodes under about 1 cm are commonly normal in cervical, axillary and inguinal sites, while nodes above 2 cm, or any hard fixed node, need prompt evaluation. Size alone never settles the diagnosis, and consistency and persistence matter as much.
Why is a supraclavicular node treated as malignant until proven otherwise?
Supraclavicular nodes are rarely reactive and are strongly linked with lymphoma, metastatic disease and tuberculosis. Early excision biopsy is therefore recommended rather than observation, because delay can allow an underlying malignancy to progress.
Which biopsy is preferred for suspected lymphoma in children?
Excision or core needle biopsy is preferred, because histology and immunophenotyping need nodal architecture. Fine-needle aspiration alone is usually inadequate for lymphoma, although it can help in suspected tuberculosis.
How long can a reactive lymph node be observed before biopsy?
A reactive node is commonly reviewed after two to four weeks of treating a suspected bacterial infection. Persistence beyond this period, or any red flag at any time, is an indication for biopsy.
Can a drug cause lymphadenopathy that mimics lymphoma?
Yes, phenytoin is a classic example, producing a pseudolymphoma picture with generalised nodes. A careful drug history forms part of every paediatric node evaluation, and any change of drug should be made under specialist advice.