A male infant presented to the pediatric otolaryngology office for evaluation of a left postauricular mass. Initially the lesion appeared to be acutely inflamed with erythema, overlying crusting, and tenderness to palpation. The child was treated with a course of antibiotics. Four weeks after the initial evaluation, the acute inflammation had resolved, but the lesion had increased in size. The child was otherwise healthy, and the parents stated that he had no systemic symptoms such as fever or weight loss. On physical examination, a 1.5-cm superficial, ovoid firm lesion was noted in the left postauricular area (Figure, A). While the lesion was attached to the skin, it was mobile over the mastoid bone. There were no middle ear abnormalities on physical examination. Ultrasonography of the lesion revealed a nonvascular, well-circumscribed 1.7 × 1.4 × 0.6-cm lesion in the soft tissue posterior to the left ear. It demonstrated a heterogenous echotexture but was predominantly hypoechoic without internal vascularity or distinct calcifications. Excisional biopsy under general anesthesia was performed owing to rapid enlargement and unclear etiology of the lesion. The lesion had distinct borders and separated easily from the surrounding soft-tissue attachments. It was completely excised, including the overlying skin. Pathologic examination revealed a neoplasm extending from the reticular dermis into the subcutaneous adipose tissue (Figure, B). There were lobules of lipidized histiocytic cells with eosinophils in a background of collagen (Figure, C). The lesion stained negatively for S-100 and CD1a (Figure, D).
Hamersley ERS, Baldassari CM. Superficial Postauricular Mass in an Infant. JAMA Otolaryngol Head Neck Surg. 2015;141(9):847-848. doi:10.1001/jamaoto.2015.1440