title: Periorbital Dermoid Cyst With Unique Trichilemmal Differentiation.
abstract: The authors describe a 4-year-old girl presenting with a 2-year history of a superomedial eyelid "bump" that appeared cystic on MRI. The clinical diagnosis was dermoid cyst, possibly of conjunctival origin. Following excision, histology showed a cyst that contained keratin and lanugo hairs in its lumen with sebaceous glands and chronic inflammation in its fibrous wall. An unanticipated finding was the presence of a trichilemmal (pilar) variety of epithelial lining that stained positively for calretinin, an immunostain that identifies trichilemmal epithelium. To the authors' knowledge this is the first case of a dermoid cyst with trichilemmal lining. This study was conducted in compliance with the rules and regulations of the Health Insurance Portability and Accountability Act and in conformity with the Oslo declaration.
authors.affiliation: Departments of *Ophthalmology and †Pathology, New York University Langone Medical Center, New York, New York; ‡Department of Ophthalmology, David G. Cogan Laboratory of Ophthalmic Pathology, Massachusetts Eye and Ear Infirmary; §Department of Pathology, Massachusetts General Hospital; and ‖Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, U.S.A.
authors.forename: Norman C
authors.initials: NC
authors.lastname: Charles
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Jakobiec
authors.forename: Payal
authors.initials: P
authors.lastname: Patel
mesh_terms: D001706:Biopsy; D002454:Cell Differentiation; D002675:Child, Preschool; D003884:Dermoid Cyst / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005142:Eyelid Neoplasms / Q000175:diagnosis*; D005143:Eyelids / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging