The objective of this study was to discuss an unusual postauricular mass in a pediatric patient. This mass had a broad differential including congenital anomaly, neoplasm, infection, and lymphovascular malformation. Atypical nodular hidradenoma is a rare adnexal tumor that is difficult to differentiate from hidradenocarcinoma. It is a rare entity, but especially rare in the pediatric population. This study aims to provide guidance on diagnosing hidradenoma and distinguishing it from hidradenocarcinoma through case presentation with a review of the literature. The patient in this report underwent wide location resection with close surveillance and has been disease-free during follow-up.