Chronic Lateral Neck Mass in an Adolescent Female.

Neck masses are a common finding in the pediatric population, with a broad differential diagnosis resulting in real diagnostic challenges. They are most frequently caused by reactive lymphadenopathy, infectious lymphadenitis, or congenital anomalies of the neck. This case report describes a 16-year-old female presenting to the pediatric emergency department with 5 weeks of right-sided neck mass. Based on her history, physical examination, and prolonged clinical course, the differential diagnosis included infectious, congenital, and neoplastic causes. The patient was ultimately diagnosed with a branchial cleft cyst and referred to a pediatric head and neck surgeon.