weight loss, night sweats, or adenopathy elsewhere are revealing ENT and respiratory symptoms such as noisy breathing (e.g., wheezing or stridor), dyspnea, sore throat, and neck pain are likewise significant Eliciting an exposure history will further inform the differential Temporal exposure to known sick contacts, or recent trauma from animal scratches and bites can contribute to the differential diagnosis Antibiotic or antiepileptic drug exposure may cause symptoms like serum sickness (e.g., fever, malaise, rash, arthralgias, nephritis) or pseudolymphoma, respectively (see Fig 48.1 ) Physical Examination The child presenting with a neck mass should have a thorough head-to-toe examination, beginning with assessment for critical illness A meticulous neck evaluation may be deferred until after completion of the remaining examination Inspection of the oral cavity should describe structures such as oral mucosa, dentition, Stensen duct (i.e., the parotid duct), and other glands Movement of the mass with swallowing or tongue protrusion is important to note Further inspection should include assessment of the scalp, ears, sinuses, and nasopharynx Evaluate remaining structures to determine if additional lesions are present The neck examination describes the location of the mass, including visual inspection and palpation while in flexion and extension Figure 48.2 diagrams common locations of neck mass Those in the supraclavicular area or the posterior triangle (superior to the clavicle, and posterior or lateral to the sternocleidomastoid), have a higher incidence of being neoplastic than those in the anterior triangle (anterior or medial to the sternocleidomastoid) Palpation provides critical characteristics of the mass including size, shape, consistency, mobility, existence, and severity of tenderness Presence of crepitation, thrill, bruit, fluctuance, or overlying skin changes should also be noted Characteristics that may be associated with malignancy include masses that are firm, larger than cm in diameter, nonpainful, progressively enlarging, ulcerating, deep to fascia or fixed to tissue, longer duration (i.e., weeks), or discovered in a newborn These criteria are sensitive but not specific for cancer