What is the appropriate workup for a 3-year-old with swollen lymph nodes?

Workup for a 3-Year-Old with Swollen Lymph Nodes

The appropriate workup for a 3-year-old with swollen lymph nodes should begin with determining if the lymphadenopathy is localized or generalized, with excisional biopsy being the recommended treatment for children with nontuberculous mycobacterial (NTM) cervical lymphadenitis, which is the most common form of NTM disease in children. 1

Initial Assessment

• Determine if lymphadenopathy is localized (one region) or generalized (two or more regions), as this significantly affects the differential diagnosis 2
• Assess lymph node characteristics including:
  • Size (nodes >2 cm are concerning) 2
  • Location (cervical nodes are most common in children) 3
  • Consistency (hard nodes may indicate malignancy) 2
  • Mobility (nodes matted or fixed to surrounding structures raise concern) 2
  • Tenderness (NTM lymphadenitis is generally unilateral and not tender) 1
• Document duration of lymphadenopathy (persistence beyond 4 weeks warrants further evaluation) 2
• Evaluate for systemic symptoms such as fever, night sweats, weight loss, or other concerning symptoms 2, 4

Epidemiology and Common Causes

• Cervical adenitis is the most common form of NTM disease in children, particularly between 1-5 years of age 1
• Approximately 80% of culture-proven NTM lymphadenitis cases are due to Mycobacterium avium complex (MAC) 1
• Most cases of lymphadenopathy in children are benign and self-limited, often due to viral or bacterial infections 5
• The most frequently encountered viral causes include cytomegalovirus (CMV) and Epstein-Barr virus (EBV) 5

Diagnostic Workup

Laboratory Studies

• Complete blood count to evaluate for leukocytosis or other abnormalities 2
• C-reactive protein and/or erythrocyte sedimentation rate to assess inflammation 2
• Tuberculosis testing, particularly if PPD tuberculin skin test is positive 1
• Consider viral serologies (EBV, CMV) if clinically indicated 5

Imaging

• Ultrasound is the preferred initial imaging modality for evaluating lymphadenopathy in children 3
• Chest radiograph should be considered, especially if there is concern for mediastinal involvement or tuberculosis 3
• For larger lymph nodes (≥5 cm) or those in difficult anatomical sites, consider more advanced imaging such as MRI or CT 1

Biopsy

• Fine-needle aspiration (FNA) may be used for initial evaluation, but has limitations 1
• Excisional biopsy without chemotherapy is the recommended treatment for children with NTM cervical lymphadenitis, with a success rate of approximately 95% 1
• Incisional biopsy alone should be avoided as it may lead to persistent clinical disease, including sinus tract formation and chronic drainage 1

Management Considerations

• For suspected bacterial lymphadenitis, antibiotics may be considered 2
• For NTM lymphadenitis, excisional surgery is the treatment of choice 1
• For children with recurrent disease or high surgical risk (e.g., risk of facial nerve involvement with preauricular nodes), a clarithromycin multidrug regimen may be considered 1
• Azithromycin may be used for certain infections in children, with dosing based on weight and specific condition 6
• Avoid corticosteroids as they can mask histologic diagnosis of lymphoma or other malignancy 2

When to Consider Malignancy

• Lymph nodes larger than 2 cm, hard, or matted/fused to surrounding structures may indicate malignancy, especially in children 2
• Supraclavicular lymphadenopathy is particularly concerning for malignancy 4
• Persistent lymphadenopathy (>4 weeks) or accompanying systemic symptoms warrants further investigation 2
• Non-Hodgkin lymphoma is the most frequent malignancy found in children with lymphadenopathy 5

Special Considerations

• If a child has granulomatous disease and a strongly positive PPD tuberculin skin test, consider anti-TB therapy while awaiting lymph node culture results 1
• For children with HIV infection, consider immune reconstitution syndrome if lymphadenopathy develops after starting antiretroviral therapy 1
• Recognize that children between 1-5 years old are most susceptible to NTM lymphadenitis due to frequent contact with NTM sources such as soil and water 1