結膜外に生じた原発性結膜上皮囊胞の1例

A Case of Primary Conjunctival Epithelial Cyst of the Orbit

はじめに

　結膜上皮囊胞は，非角化扁平上皮と杯細胞を有する皮膜をもった良性腫瘍である 1）。一般に球結膜に生じ，外傷や手術，眼表面の炎症による後天性がほとんどであり，原発性は少ない。さらに，原発性で結膜外に発生するものは極めてまれである 2）。今回われわれは，結膜外に生じた原発性結膜上皮囊胞に対して摘出術を施行したため，若干の文献的考察を含めて報告する。

　We report a case of primary conjunctival epithelial cyst of the orbit in a 31-year-old female who had noticed redness and swelling of the right upper eyelid 1 month before her presentation. A local ophthalmologist had diagnosed an inflammatory epidermal cyst and treated it with oral antibacterial therapy. The redness improved within a few days, but a subcutaneous mass remained, and the patient was referred to our hospital. Magnetic resonance imaging demonstrated a rounded, cystic lesion between the right eye and the right eyebrow. After the complete surgical excision of the lesion, the histopathological examination revealed a conjunctival epithelial cyst lined by nonkeratinized cuboidal epithelium with goblet cells. A conjunctival epithelial cyst should be considered in the differential diagnosis of a mass between the eye and the eyebrow. The present patient has not exhibited any recurrence as of 1 year after the excision.