What is the appropriate evaluation and management of a neck lump in a child?

Evaluation and Management of Neck Lumps in Children

Ultrasound is the initial imaging modality of choice for most pediatric neck masses, particularly when congenital abnormalities or superficial infections are suspected, with CT or MRI reserved for cases concerning for malignancy or deep neck infections requiring surgical intervention. 1

Initial Clinical Assessment

Key Historical Features to Elicit

• Duration of mass: Presence >2 weeks without fluctuation raises malignancy concern 2
• Associated symptoms: Fever, overlying skin erythema, recent trauma, or fluctuation in size 1
• Infectious history: Recent viral or bacterial illness suggesting reactive lymphadenopathy 2
• Constitutional symptoms: Weight loss, night sweats, or fever (type B symptoms) suggest malignancy 2

Critical Physical Examination Findings

• Size: Lymph nodes >2 cm diameter warrant heightened concern 2
• Consistency: Hard, firm, or rubbery masses are more concerning than soft, mobile nodes 2
• Mobility: Fixed masses attached to adjacent tissues suggest malignancy 2
• Location: Supraclavicular or posterior triangle masses have higher malignancy risk 2, 3
• Overlying skin changes: Ulceration is a red flag for malignancy 2

Differential Diagnosis by Category

Congenital Lesions (Most Common)

• Thyroglossal duct cysts 2, 3
• Branchial cleft cysts and arch anomalies 2, 3
• Dermoid cysts 2
• Vascular malformations and hemangiomas 2
• Lymphangiomas 4

Inflammatory/Infectious Causes

• Reactive lymphadenopathy (most common overall) 2, 3
• Bacterial lymphadenitis (Staphylococcus aureus, Group A Streptococcus) 2
• Viral infections 2
• Mycobacterial infections 2
• Cat-scratch disease 2
• Kawasaki disease 2

Neoplastic Lesions

Benign: Pilomatrixomas, lipomas, fibromas, neurofibromas, salivary gland tumors, fibromatosis colli 2, 4

Malignant (rare but critical to identify): Lymphoma, rhabdomyosarcoma, thyroid carcinoma, metastatic nasopharyngeal carcinoma 2, 4

Imaging Algorithm

First-Line Imaging: Ultrasound

Ultrasound is usually appropriate as initial imaging for:

• Suspected congenital abnormalities (differentiates solid from cystic lesions) 1
• Superficial infections 1
• Discriminating high-flow from low-flow vascular malformations 1
• Guiding fine-needle aspiration 5
• Color-flow Doppler helps characterize vascular flow in solid lesions 1

Advanced Imaging: CT or MRI

CT neck with IV contrast is usually appropriate when:

• Malignancy is suspected based on clinical features 1
• Deep neck infection or abscess requiring surgical drainage is present 1
• Shorter examination time reduces/eliminates sedation requirements compared to MRI 1, 5
• ALARA (As Low As Reasonably Achievable) radiation principles must be followed 1

MRI neck (with and without IV contrast) is usually appropriate when:

• Malignancy is suspected and soft tissue characterization is needed 1
• Deep neck abscess evaluation is required 1
• Improved soft-tissue intrinsic contrast is beneficial 5
• Evaluating for intracranial or intraspinal extension (rhabdomyosarcoma, neuroblastoma) 4

CT and MRI are equivalent alternatives and may be complementary to ultrasound 1

Imaging NOT Recommended

• FDG-PET/CT or PET/MRI: No evidence supports use for initial evaluation 1
• CTA or MRA: No evidence supports routine use (exception: time-resolved MRA for venous malformations) 1
• Catheter angiography: No evidence supports use 1

Laboratory Workup

Order when history suggests specific etiologies:

• Complete blood count 2
• Purified protein derivative (PPD) test for tuberculosis 2
• Titers for: Epstein-Barr virus, cat-scratch disease, cytomegalovirus, HIV, toxoplasmosis 2

Management Approach

Low-Risk Masses (Likely Reactive/Infectious)

Characteristics: Soft, mobile, <2 cm, associated with recent infection, no constitutional symptoms 2

Management:

• Trial of antibiotics targeting S. aureus and Group A Streptococcus if bacterial lymphadenitis suspected 2
• Advise patients/families of criteria triggering need for additional evaluation 1
• Document follow-up plan to assess resolution 1
• If no response to antibiotics: consider IV therapy, incision and drainage, or further workup 2

High-Risk Masses (Concerning for Malignancy)

Red flags requiring urgent referral to head and neck surgeon 2:

• Type B symptoms present
• Hard, firm, or rubbery consistency
• Fixed to adjacent tissues
• Supraclavicular location
• Size >2 cm
• Persistent enlargement >2 weeks
• No size decrease after 4-6 weeks
• Absence of inflammation
• Ulceration present
• Failure to respond to antibiotics
• Associated thyroid mass

Congenital Masses

Surgical excision is recommended to prevent potential growth and secondary infection 2, 3

Common Pitfalls to Avoid

• Do not delay imaging in children with concerning features—malignancy, though rare, presents as asymptomatic neck mass 6, 3
• Do not perform open biopsy before imaging and specialist consultation, as this can complicate subsequent management 1
• Do not assume all persistent nodes are benign—single dominant node persisting >6 weeks requires specialist evaluation 2, 3
• Do not overlook posterior triangle or supraclavicular nodes—these locations have higher malignancy risk 2, 3