下眼瞼に発生した単発性脂腺囊腫の1例

A case of steatocystoma simplex in the lower eyelid

要約　背景：単発性脂腺囊腫（steatocystoma simplex）は良性の皮下腫瘍で，頻度は小さい。顔面に好発するが，眼瞼に生じた報告は3例しかない。目的：下眼瞼に発生した単発性脂腺囊腫の1症例の報告。症例：16歳女性が右の下眼瞼腫瘤で受診した。1か月前からこの部位に違和感があったという。所見：視診では下眼瞼に病変はなく，触診で腫瘤が存在した。下眼瞼の反転で，瞼結膜円蓋部に境界明瞭な隆起があった。類表皮腫を疑い，腫瘤を摘出した。術中に薄い被膜がみられ，被膜とともに全摘出した。腫瘤の大きさは12mm×9mm×6mmで，病理組織学的に単発性脂腺囊腫と診断された。結論：結膜円蓋部には毛根が存在しないため，脂腺囊腫の発症に毛包の関与はなく，脂腺由来であることが推定される。

Abstract.　Purpose：To report a case of steatocystoma in the lower eyelid. Case：A 16-year-old female was referred to us for a palpable lump in the right lower eyelid. She had noticed a foreign body sensation in the lower eyelid since one month before. Findings：The right lower eyelid appeared to be normal by visual inspection. A tumor was present by palpation. When the eyelid was everted, a well-demarcated tumor was present in the fornix. The lesion was surgically removed under the tentative diagnosis of dermoid cyst. The tumor was found to be encapsulated during surgery and was totally excised. Its size was 12 mm×9 mm×6 mm. It was diagnosed with steatocystoma histopathologically. Conclusion：There are only three reported cases of steatocystoma in the eyelid. It appears to have originated from the sebaceous gland in the present case.