Reactive Lymph Node in the Neck
A reactive lymph node in the neck is a benign enlargement of a lymph node that occurs as a normal immune response to infection, inflammation, or other stimuli, characterized by preservation of lymph node architecture with possible mild expansion of the mantle zone. 1
Characteristics of Reactive Lymph Nodes
- Reactive lymph nodes typically measure less than 1.5 cm in shortest axis 1, 2
- On ultrasound, the presence of a fatty hilum is a classic benign feature 1
- Reactive lymphadenopathy commonly occurs with respiratory infections and typically resolves with the infectious symptoms or within days of completing treatment 2
- Reactive lymph nodes may persist for weeks to months after successful treatment of the underlying cause 1
- Reactive lymph nodes maintain normal lymph node architecture but may show expansion of certain zones 1, 3
Differentiating Reactive from Malignant Lymph Nodes
Benign Features
- Size less than 1.5 cm 2, 1
- Preservation of fatty hilum on imaging 1
- Mobile (not fixed to adjacent tissues) 2
- Soft to moderately firm consistency 2
- No ulceration of overlying skin 2
- May be tender to palpation if associated with acute infection 2
Suspicious Features (Concerning for Malignancy)
- Fixation to adjacent tissues 2
- Firm consistency 2
- Size greater than 1.5 cm 2
- Ulceration of overlying skin 2
- Persistence beyond 2 weeks without improvement 2
- Absence of infectious symptoms or recent infection 2
Common Causes of Reactive Lymphadenopathy
- Upper respiratory tract infections 2
- Dental problems or infections 2
- Trauma (including insect bites) 2
- Exposure to certain animals 2
- Autoimmune conditions 4
- Medication reactions 4
- Idiopathic processes 4
Evaluation and Management
Initial Assessment
- Careful history to identify potential infectious causes or concerning symptoms 2
- Physical examination to assess characteristics of the lymph node and look for other sites of lymphadenopathy 5
- Observation is appropriate for typical benign-appearing lymph nodes 1
When to Consider Further Evaluation
- Lymph node persisting for ≥2 weeks or of uncertain duration 2
- Size >1.5 cm 2
- Fixed to adjacent tissues 2
- Firm consistency 2
- Ulceration of overlying skin 2
- Absence of infectious symptoms 2
- Presence of concerning symptoms (unexplained weight loss, night sweats, dysphagia, voice changes) 2
Management Options
- For typical reactive nodes: observation with follow-up in 2-4 weeks to confirm resolution 2, 1
- For nodes with suspected bacterial infection: a single course of broad-spectrum antibiotics with reassessment within 2 weeks 2
- For persistent nodes after antibiotics: further workup for possible malignancy 2
- For nodes with highly suspicious features: imaging and/or biopsy 1
Common Pitfalls to Avoid
- Overtreatment of benign reactive lymphadenopathy with unnecessary biopsies or excisions 1
- Prescribing antibiotics without evidence of bacterial infection 2
- Failure to follow up on persistent lymphadenopathy 2, 1
- Mistaking reactive lymphadenopathy for lymphoma (one of the most commonly misdiagnosed cancers) 4, 3
- Overlooking that partial resolution after antibiotics may represent infection in an underlying malignancy 2
Follow-up Protocol
- For nodes treated with antibiotics: reassessment within 2 weeks 2
- If complete resolution: one additional follow-up in 2-4 weeks to monitor for recurrence 2
- For benign-appearing nodes: repeat imaging in 3-6 months to confirm stability 1
- For nodes showing concerning changes (increasing size, loss of fatty hilum, development of necrosis): consider biopsy or specialist referral 1