Imaging Yield and Surgical Outcomes of Nasal, Medial Brow, Forehead, and Scalp Dermoid Cysts

Dermoid cyst (DC) is a congenital cyst with the potential to have intracranial extension (ICE). This study aims to evaluate the imaging yield and surgical outcomes of nasal, medial brow, forehead, and scalp DCs. Retrospective review of craniofacial DCs treated at our institution between 1992 and 2024. A total of 117 patients (57 females) were included. The median age at cyst detection and removal were 4.8 months (IQR 3.6-9.6) and 1.8 years (IQR 0.9-5.3), respectively. In 42 patients, parents have noticed the presence of the cyst immediately after birth. Cyst wall rupture during surgical removal was reported in 15.4%. The median follow-up time was 1.3 months (IQR 0.5-12.2). Three patients experienced recurrence. No postoperative complication was reported. The regions with the highest prevalence of ICE were the forehead, frontotemporal scalp, and nasal region. The lateral frontal/temporal scalp had a 33.3% rate of ICE. Midline forehead/scalp lesions demonstrated a higher risk of ICE compared to their lateral equivalents (54.5% vs 17.5%, = .03). The sensitivity and specificity of magnetic resonance imaging (MRI) were 100% and 95.7%, while for computed tomography (CT scans) were 72.7% and 96.5%. The Area Under the Curve for MRI was 0.978, and for CT was 0.846. The sensitivity and specificity of ultrasound were 50% and 100%. Midline forehead/scalp DCs are more prone to extend intracranially than lateral DCs. MRI had a higher sensitivity and specificity than CT scans in detecting ICE. Routine screening imaging should be considered in midline forehead/scalp, lateral frontal/temporal, and nasal DCs.