Scalp dermoid cysts are common etiologies of subcutaneous lump and bump lesions in the pediatric population, with incidence ranging from 15 to 22% (Crawford, 1990; McAvoy & Zuckerbraun, 1976). Midline scalp dermoid cysts have high risk for intracranial extension, with incidence reported to be 39–57% of cases (Wood, Couture, & David, 2012; Posnick, Bortoluzzi, Armstrong, & Drake, 1994). The following case illustrates a healthy thirteen-year-old boy who presented with asymptomatic enlarging subcutaneous posterior scalp mass who was consented for excision of the mass without pre-operative imaging, and was found to have an intracranial dermoid sinus tract intra-operatively. Post-operative imaging found an intracranial dermoid nodule which entailed an otherwise avoidable second-stage surgery to achieve complete resection.