眼付属器膨大細胞腫の2例

Two cases of oncocytoma in or near the lacrimal gland

要約　目的：涙腺または涙丘部に膨大細胞腫が生じた2例の報告。

症例：1例は67歳の女性，他の1例は65歳の男性である。第1例は9年前に左眼瞼が腫脹し，左涙腺の膨大があった。血液の甲状腺刺激ホルモン受容体抗体（TRAb）の軽度上昇があり，バセドウ病関連涙腺炎と診断された。副腎皮質ステロイドの内服で軽快した。眼瞼腫脹の再燃が以後3回あり，MRIで左涙腺部の腫瘤の増大があり，腫瘍を全摘出した。切除組織にはHE染色で好酸性顆粒状の細胞質と，異型に乏しい円形の核を伴う多角形大型細胞があり，膨大細胞腫と診断した。第2例は約3か月の経過で出現した右涙丘部の腫瘤で，生検では第1例と同様の所見があり，膨大細胞腫と診断した。両症例とも，術後1年間に再発はない。

結論：膨大細胞腫が，1例は涙腺，他の1例は涙丘に生じた。稀な疾患であるが，眼瞼または涙腺部に生じる腫瘍として留意する必要がある。

Abstract　Purpose：To report 2 cases of oncocytoma in the lacrimal gland or near the lacrimal caruncle.

Cases：One was a 67-year-old female and the other was a 65-year-old male. The first case had developed swelling of the left upper eyelid associated with swollen lacrimal gland. The circlating blood showed slightly elevated value of TRAb or antibody to TSH receptor. She was diagnosed with lacrimal adenitis associated with Basedow disease. The lesion subsided after systemic treatment with cystemic corticosterodi. Similar episodes recurred three times during the following 9 years. The lacrimal tumor was totally excised after MRI showed enlarged tumor in the lacrimal gland. The lesion showed proliferation of oxyphilic cells with round nuclei in addition to eosinophilic granular cytoplasm. The second case showed a tumor in the right caruncle. The lesion was excised and was diagnosed as oncocytoma with similar findings. No recurrence had developed in both cases during one year of follow-up.

Conclusion：Oncocytoma in the eyelids, including ones involving the lacrimal gland, has to considered in the differential diagnosis of ocular adnexal tumors.