Facial Mass in an Infant

Abstract

A male infant presented with a 4-day history of a right-sided facial mass. The child had no preceding illnesses and was feeding and gaining weight appropriately. His medical history was significant only for a small hemangioma on the dorsal aspect of his left foot. On physical examination, the infant appeared healthy. Mild fullness was observed in the right preauricular region extending anteriorly. The affected region was firm and slightly warm on palpation but nontender and without overlying skin changes. Facial movement was intact and symmetrical. Findings from the remainder of his head and neck examination were otherwise unremarkable. The child was started on treatment with amoxicillin for possible parotitis, with plans for magnetic resonance imaging (MRI) if no improvement was seen. The child’s lesion failed to resolve with antibiotics and instead began to enlarge, prompting his presentation to the emergency department, where examination demonstrated extension of the right facial mass postauricularly, as well as belowtheangleof themandibleand to theupperneck.Results from laboratory tests were significant for an elevated white blood cell count (17200/μL[17.2 × 109/L]), erythrocytesedimentationrate (66 mm/h), andC-reactiveprotein level (0.336mg/L [3.2nmol/L]).Both computed tomographic (CT) images andMRI of the neck were obtained, which showed a partially necrotic, expansile lesion centeredwithin the right mandibular ramusmeasuring approximately 4 × 2.3 × 2.3 cmwith a large conglomeration of lymph nodes posteriorly extending to the supraclavicular area (Figure). A biopsy of themass was then performed. What is your diagnosis? A B