lymphadenopathy

Lymphadenopathy is the enlargement of one or more lymph nodes. In adults, a node is generally considered enlarged if it is more than about 1 centimeter in the neck or 1.5 centimeters in the groin, though normal size can vary. Lymphadenopathy can be localized to a region or generalized, involving several noncontiguous regions. The condition reflects an immune response to infection, inflammation, malignant disease, or rarely other systemic illnesses.

Causes are broad. Infections are the most common cause and include viral illnesses, bacterial infections such as streptococcal pharyngitis or tuberculosis, and localized infections near the affected lymph node. Autoimmune diseases (for example, rheumatoid arthritis or systemic lupus erythematosus) can produce persistent enlargement. Malignancies, including lymphoma and metastases from solid tumors, may present as persistent or enlarging nodes. Drugs, immunizations, and other conditions can also cause reactive lymphadenopathy. Nodes may be tender with acute infection or non-tender and firm when malignancy or granulomatous disease is involved.

Evaluation begins with a careful history and physical examination. Red flags include hard, fixed nodes; supraclavicular or generalized enlargement; rapidly enlarging nodes; and associated systemic symptoms such as fever, night sweats, or weight loss. Baseline tests may include complete blood count, inflammatory markers, and targeted infectious tests (for example, HIV, TB testing). Imaging, such as ultrasound, helps characterize nodes. Biopsy, including fine-needle aspiration or excisional biopsy, is recommended if malignancy is suspected or if lymphadenopathy persists despite initial management.

Management depends on the underlying cause. Many reactive nodes resolve with treatment of infection or withdrawal of offending agents. Persistent, enlarging, or suspicious nodes require specialist evaluation. Prognosis varies with etiology; most benign lymphadenopathy resolves, while malignant causes require oncologic care.