Intraorbital Dermoid Cyst With Zygomaticofrontal Suture Erosion in an Adult.

Background: Dermoid cysts are squamous epithelium-lined sacs that result from abnormal migration of ectodermal cells. They are typically superficial and present in children. This study reviews a rare patient with a congenital dermoid cyst occurring as a superolateral intraorbital and extraconal mas.

Method: Clinical report and review of the literature.

Results: A 27-year-old male presented with progressive left hypoglobus, proptosis, and diplopia. On computed tomography, a 2.0 × 2.1 × 1.1 cm well circumscribed mass centered on, and extended into, the frontozygomatic suture with smooth remodeling of the frontal bone. Magnetic resonance imaging showed heterogeneous T1 and T2 hyperintensity with hypointensity on fat suppression. A dermoid cyst originating from the frontozygomatic suture was suspected. Excision was performed through a left orbitocranial approach with a lateral orbitotomy through an upper eyelid crease incision. The mass occurred in the superior-lateral portion of the left orbit and originated from the intraorbital surface of the zygomaticofrontal suture line with significant bony remodeling without osseous transgression. The mass was removed completely including the lateral portion of the zygomaticofrontal suture. Pathologic examination was consistent with a dermoid cyst. Postoperative examination revealed resolution of his presenting headaches and diplopia.

Conclusion: Congenital dermoid cysts occurring within the craniofacial region occur most commonly in the lateral orbit involving the superficial surface of the frontozygomatic suture. This patient represents the rare occurrence of a dermoid cyst originating from the deep surface of the frontozygomatic suture, resulting in delayed presentation and orbital symptoms of hypoglobus and diplopia. Definitive treatment remains complete surgical excision.