Craniofacial Dermoid Cysts: Histological Analysis and Inter-site Comparison

Introduction: Dermoid cysts are common, benign, embryologically derived soft tissue cysts that can arise at a variety of craniofacial sites. It is not known whether specific histological variations exist between the different craniofacial sites. This study aims to establish whether inter-site histologic differences exist between periorbital, nasal, scalp, and postauricular dermoid cysts and analyze these in context of their distinct embryological origin and varied clinical presentation. Methods: A retrospective review of craniofacial dermoid cysts was performed. Using light microscopy with hematoxylin and eosin staining, histological appearance was directly compared between craniofacial sites. Results: All (n = 16) cysts contained keratinizing, stratified squamous epithelial lining, intraluminal keratin, and hair. Sebaceous glands were commonly present (n = 13). Eccrine (sweat) glands were less common (n = 3). Structures of mesodermal origin were seen in three periorbital cysts. Only the six ruptured cysts showed evidence of inflammation. Conclusions: Histological properties of dermoid cysts are conserved between craniofacial sites (periorbital, nasal, scalp, and postauricular). This reflects the consistency of ectodermal inclusion during early embryological development, which is independent of specific craniofacial site or surrounding anatomical structures.