External Angular Dermoid Excision via Sub-brow Approach: An Excellent Aesthetic Outcome

Abstract

External angular (frontozygomatic) dermoid cysts are congenital Choristomas arising from ectodermal sequestration along embryonic suture lines. They typically present as painless, slow-growing swellings near the lateral eyebrow, often noticed in childhood or early adulthood. While benign, their proximity to the orbital rim and frontal bone warrants careful evaluation for possible bony remodelling or intracranial extension. We discuss the case of a young male presenting with a gradually progressive, non-tender swelling at the right lateral eyebrow. Preoperative imaging with computed tomography revealed a well-defined, cystic lesion located superficial to the frontozygomatic suture without intraorbital extension. Surgical excision was performed via a sub-brow incision to ensure optimal cosmetic outcome. The cyst was dissected meticulously, preserving capsule integrity to prevent recurrence. The postoperative course was uneventful, with an excellent aesthetic result and a well-concealed scar. Microscopic examination confirmed a dermoid cyst lined by stratified squamous keratinised epithelium containing adnexal structures such as sebaceous glands and hair follicles, consistent with a benign developmental choristoma. The sub-brow approach offers a safe and cosmetically favourable route for superficial lesions. This report highlights the diagnostic nuances, surgical strategy, and review of outcomes that support the conservative yet precise management of such cysts.