What is the appropriate workup for a patient presenting with neck necrotic lymphadenopathy?

Workup of Neck Necrotic Lymphadenopathy in Adults

For an adult presenting with neck necrotic lymphadenopathy, immediately obtain contrast-enhanced CT or MRI of the neck, chest, and abdomen, perform fine-needle aspiration (FNA) for tissue diagnosis, and conduct a targeted physical examination including visualization of the larynx, base of tongue, and pharynx to evaluate for head and neck squamous cell carcinoma or lymphoma. 1, 2

Initial Clinical Assessment

Identify high-risk features that mandate urgent workup:

• Lymph node present ≥2 weeks without infectious etiology 1, 2
• Physical characteristics: fixation to adjacent tissues, firm consistency, size >1.5 cm, or ulceration of overlying skin 1, 2
• Systemic B symptoms: fever, drenching night sweats, unexplained weight loss >10% over 6 months 1, 2
• Necrotic lymphadenopathy specifically raises concern for metastatic squamous cell carcinoma, tuberculosis, or Kikuchi disease (histiocytic necrotizing lymphadenitis) 3, 4, 5

Document specific history elements:

• Duration and progression of lymphadenopathy 6, 7
• Presence of B symptoms, fatigue, pruritus, alcohol-induced pain 1
• Occupational exposures, travel history, animal contacts 6, 7
• HIV risk factors, immunosuppression status 1, 2

Mandatory Imaging

Obtain contrast-enhanced CT of neck, chest, and abdomen immediately for any patient with necrotic lymphadenopathy, as this is considered high-risk for malignancy. 1, 2 This imaging:

• Evaluates extent of disease and identifies additional involved nodal stations 1, 2
• Assesses for primary tumor sites in the upper aerodigestive tract 2
• Identifies mediastinal or abdominal involvement suggesting lymphoma 1

Consider PET-CT if initial CT shows suspicious findings or to complete staging once malignancy is confirmed, as it has high sensitivity for detecting additional disease sites and bone marrow involvement. 1, 2

Essential Laboratory Testing

Obtain comprehensive initial labs:

• Complete blood count with differential (assess for leukocytosis, lymphocytosis, or cytopenias) 1, 2, 6
• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) 1, 2, 5
• Comprehensive metabolic panel including liver enzymes, alkaline phosphatase, LDH, albumin 1, 2
• Mandatory infectious disease screening: hepatitis B, hepatitis C, and HIV serology before any treatment 1, 2
• β2-microglobulin if lymphoma suspected (prognostic marker) 2

Tissue Diagnosis Strategy

Perform FNA as the initial tissue sampling method rather than open biopsy, as recommended by the American Academy of Otolaryngology-Head and Neck Surgery. 1, 2 However, recognize important limitations:

• FNA of necrotic tissue may yield non-diagnostic results requiring repeat sampling 3
• If FNA is non-diagnostic or shows only necrosis, proceed to core needle biopsy or excisional biopsy to obtain adequate tissue for histology and immunohistochemistry 1, 2
• Ensure sufficient tissue for: routine histology, immunophenotyping (CD3, CD20, CD30, CD15, CD68, MPO), and potential molecular studies 1, 2, 5

Critical pitfall to avoid: Never assume necrotic lymphadenopathy is benign without definitive tissue diagnosis, as malignancy (particularly metastatic squamous cell carcinoma) commonly presents with necrosis. 2, 3

Targeted Physical Examination

The otolaryngologist must perform direct visualization of:

• Laryngeal mucosa 1, 2
• Base of tongue 1, 2
• Pharynx (nasopharynx, oropharynx, hypopharynx) 1, 2

This examination identifies occult primary tumors in the upper aerodigestive tract that commonly metastasize to cervical lymph nodes with necrotic features. 1, 2

Additional Staging Procedures (If Lymphoma Suspected)

If imaging and clinical features suggest lymphoma:

• Bone marrow biopsy is not required if PET-CT is performed, as PET has high sensitivity for marrow involvement 1
• However, bone marrow aspirate and biopsy (≥20 mm) are mandatory if PET-CT unavailable 1, 2
• Chest X-ray (though CT chest already obtained) 1

Management of Non-Diagnostic Initial Workup

If initial FNA shows only necrosis without definitive diagnosis:

• Proceed immediately to excisional biopsy rather than repeating FNA 2, 3
• Do not prescribe empiric antibiotics without clear bacterial infection, as this delays malignancy diagnosis and provides false reassurance 1, 2, 8
• Tuberculosis testing should be considered given TB can cause necrotic lymphadenopathy 6, 3

Differential Diagnosis Considerations

Necrotic cervical lymphadenopathy has three primary etiologies:

1. Metastatic squamous cell carcinoma (most common malignant cause) - requires upper aerodigestive tract examination 2, 3
2. Lymphoma (Hodgkin or high-grade non-Hodgkin) - requires comprehensive staging 1, 2
3. Infectious/inflammatory causes:
   • Tuberculosis - obtain tuberculosis testing 6
   • Kikuchi disease (histiocytic necrotizing lymphadenitis) - benign, self-limited, more common in young adults, associated with fever and elevated ESR 4, 5
   • Bacterial lymphadenitis with abscess formation 6, 7

Distinguishing features: Kikuchi disease typically shows fever, elevated ESR/LDH, decreased WBC with increased lymphocyte proportion, and responds to glucocorticoids with temperature normalization in 1-4 days. 5 However, tissue diagnosis is mandatory to exclude malignancy before considering this diagnosis.

Timeline and Follow-Up

Urgent referral to otolaryngology is required for any neck mass present ≥2 weeks, as delays in diagnosis of head and neck cancer significantly impact outcomes. 1, 2 The workup should be completed expeditiously:

• Imaging within days of presentation 1, 2
• Tissue diagnosis within 1-2 weeks 2
• Definitive diagnosis and treatment planning within 3-4 weeks of initial presentation 2