What is the cause of lymphadenopathy (lymph node enlargement) in the neck?

From the Guidelines

Lymphadenopathy in the neck should be considered malignant until proven otherwise, and a prompt diagnostic workup is essential to optimize outcomes, as emphasized by the American Academy of Otolaryngology-Head and Neck Surgery 1. When evaluating lymphadenopathy in the neck, it is crucial to consider the patient's age, medical history, and physical examination findings. The most common causes of lymphadenopathy in the neck include infections, autoimmune disorders, and malignancies. However, in adults, particularly those over 40 years old with a smoking history, the diagnosis overwhelmingly favors a malignancy 1.

Key Considerations

• Persistent lymphadenopathy (lasting more than 4 weeks), nodes larger than 2 cm, or nodes that are hard, fixed, or painless may warrant further investigation 1.
• Imaging studies, such as contrast-enhanced neck CT or contrast-enhanced neck MRI, are recommended for patients with a neck mass deemed at risk for malignancy 1.
• A complete blood count, ultrasound, or biopsy may also be necessary to determine the underlying cause of lymphadenopathy.
• Treatment depends on the specific diagnosis, ranging from antibiotics for bacterial infections to more targeted therapies for conditions like tuberculosis, autoimmune disorders, or malignancies.

Diagnostic Approach

• The American Academy of Otolaryngology-Head and Neck Surgery recommends a contrast-enhanced neck CT or contrast-enhanced neck MRI for patients with a neck mass deemed at risk for malignancy 1.
• Ultrasound may be considered an option for initial imaging in suspected thyroid or salivary masses or as an adjunct to expedite sampling 1.
• Fine-needle aspiration of the palpable mass or node may be performed in parallel with imaging for timely diagnosis 1.

Patient Management

• Patients with lymphadenopathy in the neck should be referred to a head and neck cancer specialist for further evaluation and management 1.
• While waiting for medical evaluation, patients can take over-the-counter pain relievers like acetaminophen or ibuprofen for discomfort, but should avoid self-diagnosis as neck lymphadenopathy can be associated with numerous conditions ranging from benign to serious.

From the Research

Causes of Lymphadenopathy in the Neck

• Lymphadenopathy in the neck can be caused by various factors, including malignancy, infection, and autoimmune disorders, as well as medications and iatrogenic causes 2.
• The history and physical examination alone usually identify the cause of lymphadenopathy, and when the cause is unknown, lymphadenopathy should be classified as localized or generalized 2.
• Localized lymphadenopathy in the neck should be evaluated for etiologies typically associated with the region involved according to lymphatic drainage patterns 2.

Evaluation and Diagnosis

• A systematic approach to the cause of cervical lymphadenopathy, which includes pattern of lymph node enlargement, lymph node characteristics, systemic symptoms, and extranodal abnormalities, can be very useful in arriving at the correct diagnosis 3.
• Fine-needle aspiration cytology (FNAC) can play a positive role in the diagnosis of pediatric patients with lymphadenopathy in the head and neck region, with a sensitivity and specificity of 100% in malignant cases 4.
• Core biopsy is an effective tool for investigation and can be used as a first-line investigation of choice, reducing the need for patients to undergo surgery and offering a faster diagnosis 5.

Risk Factors and Management

• Risk factors for malignancy include age older than 40 years, male sex, white race, supraclavicular location of the nodes, and presence of systemic symptoms such as fever, night sweats, and unexplained weight loss 2.
• Antibiotics may be used to treat acute unilateral cervical lymphadenitis, especially in children with systemic symptoms, while corticosteroids have limited usefulness in the management of unexplained lymphadenopathy and should not be used without an appropriate diagnosis 2.
• A thorough clinical history, physical examination, laboratory studies, and imaging can help narrow a broad differential diagnosis and identify when enlarged lymph nodes may be associated with pathology 6.