Is a computed tomography (CT) head and neck scan a reasonable diagnostic step for a swollen lymph node?

CT Head and Neck for Swollen Lymph Node Evaluation

Yes, CT head and neck with IV contrast is reasonable and represents the preferred initial imaging modality for evaluating a swollen lymph node in an adult, particularly given the risk of head and neck malignancy. 1

Primary Imaging Recommendation

Contrast-enhanced CT neck is the imaging study of choice for a palpable neck mass in adults. 1 The American College of Radiology guidelines specifically endorse this approach due to:

• Superior spatial resolution that allows detailed anatomic delineation of the mass and surrounding structures 1
• Comprehensive coverage from the top of the frontal sinuses to the aortic arch, capturing both the primary site and regional lymph node basins 1
• Ability to distinguish vessels from lymph nodes and confirm vascular relationships 1
• Detection of deep neck pathology that may not be accessible by ultrasound 1

Why "Head and Neck" Coverage Matters

The extended coverage from skull base through the neck is critical because:

• Lymph node metastases require identification of the primary tumor site, which may be located anywhere in the upper aerodigestive tract 1
• Isolated head imaging without neck coverage is inadequate for staging regional lymphadenopathy 1
• The distribution pattern of abnormal lymph nodes helps refine the differential diagnosis and guides the search for an unknown primary malignancy 1

Contrast Enhancement is Essential

IV contrast should be used unless contraindicated because: 1

• It better outlines the soft tissue extent of disease 1
• It improves detection of mediastinal and hilar adenopathy 1
• Non-contrast CT provides insufficient evaluation of soft tissue disease 1
• Dual-phase imaging (without and with contrast) is typically unnecessary 1

Risk Stratification for Malignancy

The American Academy of Otolaryngology-Head and Neck Surgery identifies high-risk features that make imaging particularly important: 1, 2

• Physical characteristics: Fixation to adjacent tissues, firm consistency, size >1.5 cm, ulceration, or matted nodes 1, 2
• Duration: Mass present ≥2 weeks or of uncertain duration 1
• Age: Patients >40 years have significantly increased malignancy risk 2
• Imaging features: Necrotic centers, extracapsular extension, irregular borders, loss of fatty hilum 2

Common Pitfalls to Avoid

• Do not assume benign disease in younger patients - HPV-related oropharyngeal cancers occur in younger populations without traditional risk factors 1, 2
• Do not delay imaging with empiric antibiotics unless clear signs of bacterial infection (warmth, erythema, fever) are present 1
• Do not order isolated head CT - this misses the neck lymph node basins essential for staging 1
• Do not skip contrast unless medically contraindicated - non-contrast studies have limited soft tissue evaluation 1

Next Steps After Imaging

Following CT neck with contrast: 1, 2

• Fine-needle aspiration (FNA) or core biopsy should be performed on suspicious nodes for definitive diagnosis 2
• Examination of the upper aerodigestive tract under anesthesia may be needed if FNA and imaging don't identify a primary site in high-risk patients 1
• Consider chest CT for high-risk tumors to evaluate for distant metastases or second primary lung cancer 1

When Alternative Imaging May Be Considered

• Ultrasound can be useful for superficial nodes and may guide FNA, but has limited access to deep neck structures 1, 3, 4
• MRI offers superior soft tissue contrast but is not superior to CT for initial lymph node evaluation 1, 5
• PET/CT is not an initial imaging study but may be useful for detecting unknown primaries or staging advanced disease 1