Zygomatic bone deformation caused by a periorbital epidermoid cyst in a child: a case report and literature review

Epidermoid and dermoid cysts are common congenital lesions of the pediatric periorbital region arising from ectodermal inclusion during embryologic development. Although these lesions originate in the soft tissue, chronic pressure from long-standing masses may induce cortical depression or remodeling of adjacent craniofacial bones, particularly in young children with malleable skeletal structures. We report a case of a 26-month-old girl presenting with a small periorbital epidermoid cyst associated with pressure-induced depression of the zygomatic surface. Radiologic evaluation revealed a well-circumscribed cystic lesion abutting the frontal process of the zygoma with smooth cortical indentation and no features suggestive of aggressive osseous pathology. Complete excision was performed through a lateral brow approach with preservation of the periosteum. Histopathologic examination confirmed an epidermoid cyst. Postoperative follow-up demonstrated progressive spontaneous restoration of the zygomatic contour without the need for bone grafting or alloplastic materials, reflecting the osteogenic potential of the pediatric periosteum. This case emphasizes the importance of distinguishing secondary pressure-related bone remodeling from true intraosseous lesions in the pediatric craniofacial region and highlights the capacity for natural osseous recovery following removal of the compressive source. A brief review of relevant embryologic and radiologic considerations is also provided.