The differential diagnosis for head and neck masses in children is very broad. Thus, this common clinical finding can be a difficult diagnosis to determine. Thorough history and physical examination are extremely important for identifying the underlying etiology of the mass, and they help guide further evaluation and therapy. Most head and neck masses in children have an infectious/inflammatory cause. However, congenital neck masses and neoplasms occur, many of which require surgical excision or biopsy for diagnosis and treatment.
CONSIDERATIONS IN DIFFERENTIAL DIAGNOSIS
There are many different approaches to the differential diagnosis of pediatric neck masses, including by age, location, and acuity. Although a host of relatively rare head and neck malignancies occur in children, neonates and young infants who present with neck masses at or close to the time of birth most likely have congenital abnormalities such as branchial cleft cysts, thyroglossal duct cysts, or vascular anomalies (see Chapter 367). However, it is important to remember that cystic congenital neck masses most commonly present later in life, when they initially become infected. Infants commonly develop infectious neck masses, including abscesses that usually occur from suppuration of lymph nodes. Neck abscesses in infants can occur throughout the neck (Fig. 368-1) and, of those that fail to respond to empiric antibiotics, typically are caused by Staphylococcus aureus and more rarely by Streptococcus pyogenes. These abscesses are treated with appropriate antibiotic therapy including methicillin-resistant S aureus (MRSA) coverage and with surgical drainage when necessary. Knowing the pattern of clindamycin resistance among MRSA isolates in the geographic region is critical when considering initial therapy. Fibromatosis colli, or sternomastoid tumor of infancy, commonly presents with a firm lateral neck mass and neck stiffness or frank torticollis (Fig. 368-2). Ultrasonographic finding of a solid mass in the sternocleidomastoid muscle is reassuring, as the diagnosis is primarily a clinical one. Early diagnosis and physiotherapy can prevent or reverse torticollis and associated cranial deformity. The most common malignancies that present as neck masses in infants are blue-cell tumors, which include neuroblastoma, rhabdomyosarcoma, and lymphoma (see discussion of malignant neoplasms below).
Suppurative adenitis/neck abscess in an 8-month-old child.
Firm swelling within the sternomastoid muscle in a 4-week-old child with sternomastoid tumor of infancy (fibromatosis colli).
Neck masses in preschool children usually are inflammatory in nature, although congenital masses may present for the first time as well. Reactive lymphadenopathy is extremely common, particularly in the setting of upper respiratory infections, and nontuberculous mycobacterial adenitis occurs primarily in this group age. Older children and adolescents with neck masses usually have enlarged cervical lymph nodes as a reactive process that is secondary to viral or bacterial infection. However, children in this older ...