Surgical approach to congenital nasal dermoid sinus cyst in adult with external rhinoplasty and endoscopic approach: a case report.

Introduction and importance: Nasal dermoid sinus cysts (NDSCs) are rare congenital nasal lesions which typically arise in early childhood. Complete surgical excision is the only therapy, and many approaches have been used according to the location and the extension of the mass. Several studies have advocated external rhinoplasty and endoscopy. Case presentation: A 21-year-old female presented with a mass on the root of the nose, which appeared since childhood, and enlarged after puberty. Investigations including imaging revealed a lobulated mass extending from the osteocartilaginous junction towards the nasion, affecting the left lateral nasal wall. And its upper pole was resting on the floor of the left frontal sinus. Complete resection was performed using external rhinoplasty and endoscopy approaches, which improved esthetic results. Lateral osteotomy was used to compensate for the lateral nasal bone loss by narrowing the width of the nose. After 10 weeks of follow-up, no complications occurred, and the patient was satisfied with the cosmetic results. Clinical discussion: Nasal dermoid sinus cysts are congenital midline nasal lesions that can present as an isolated mass, or associated with intracranial extension. External rhinoplasty and endoscopy approaches are recommended for complete excision of NDSCs extending to the anterior skull base, especially when there is no intracranial involvement or in case of small intracranial extension. These two methods allow for repairing bone defects of the anterior skull base and improve esthetic results. However, in cases of large intracranial extension, craniotomy is preferred. Conclusion: The surgical approach used in the treatment of nasal dermoid sinus cysts should be a minimally invasive technique that reduces bone morbidity and provides good cosmetic results.