Tarsal Dermoid Cyst of the Upper Eyelid in an Adult

A 56-year-old man with familial adenomatous polyposis presented with a right upper eyelid mass that recurred 1 year after 2 attempted transconjunctival excisions with an outside surgeon. Examination demonstrated a cystic anterior lesion visible below the conjunctiva causing mechanical ptosis (panel A). The remaining ophthalmologic examination was unremarkable. The patient underwent excision of the mass via an eyelid crease incision. On dissection of the preseptal plane, the lesion appeared cystic (panel B) and was found to involve full-thickness tarsus. The lesion was excised in toto, leaving a central, one-third tarsal defect. Re-approximation of the tarsal edges was attempted; however, this resulted in an eyelid kink. Allo- and autografts were considered, but the decision was made to allow secondary intention healing. Histopathological examination of the specimen revealed a cystic lesion lined by stratified squamous epithelium with cutaneous adnexal structures in the fibroconnective tissue wall, including sebaceous glands at 80× magnification (panel C), diagnostic of a dermoid cyst. The presence of adnexal structures distinguishes this lesion from more commonly seen tarsal epithelial cysts in adults, which lack these structures. The patient had resolution of the ptosis at 1-month follow-up (panel D). Eyelid dermoid cysts involving the tarsus have only been reported in the literature in children. There are reports of eyelid dermoid cysts in adults that do not involve the tarsus. To the authors’ best knowledge, this is the first reported case of an eyelid dermoid cyst with tarsal involvement in an adult patient.