Normal lymph nodes in the neck are usually less than 1 cm in length Infections involving the pharynx, salivary glands, and scalp often cause tender enlargement of neck nodes Enlarged nodes are common in HIV-infected persons Except for the occasional node that suppurates and requires incision and drainage, treatment is directed against the underlying infection An enlarged node (larger than 1 5 cm) or node with a necrotic center that is not associated with an obvious infection should be further evaluated, especially if the patient has a history of smoking, alcohol use, or prior cancer Other common indications for FNA biopsy of a node include its persistence or continued enlargement Common causes of cervical adenopathy include tumor (squamous cell carcinoma, lymphoma, occasional metastases from non-head and neck sites) and infection (eg, reactive nodes, mycobacteria, and cat-scratch disease) Rare causes of adenopathy include Kikuchi disease (histiocytic necrotizing lymphadenitis) and autoimmune adenopathy