経涙囊アプローチで摘出した眼窩筋円錐内腫瘍の1例

A case of orbital tumor located within the muscle cone and removed by transdacryocystic approach

要約　目的：眼窩内下壁から涙囊経由で摘出した眼窩筋円錐内腫瘍の症例の報告。症例：61歳女性が右眼視力低下で紹介され受診した。3年前から右眼窩腫瘍を指摘されていた。所見：矯正視力は右0.4，左1.5であり，眼窩内下方からの視神経圧迫によると思われる視野異常があった。右眼に上転と内転障害があった。磁気共鳴画像検査（MRI）で右眼窩筋円錐内に前後径26mm，左右径22mm，上下径21mmの腫瘤があり，海綿状血管腫が疑われた。腫瘍摘出は，眼窩内下壁経由で涙囊を切断し，摘出後に縫合する方法で行った。術後の視野と眼球運動は改善し，視力は0.5になり，両眼単一視野は50°まで拡大した。流涙はなく，1年後の涙道内視鏡で狭窄や閉塞はなかった。結論：眼窩内の筋円錐内腫瘍を涙囊経由で摘出することで，術野が確保され，導涙機能が維持できた。

Abstract.　Purpose：To report a case of orbital tumor located within the muscle cone and removed by transdacryocystic approach. Case：A 61-year-old female was referred for impaired vision in her right eye. She had been diagnosed with orbital tumor 3 years before. Findings：Corrected visual acuity was 0.4 right and 1.5 left. Visual field was impaired suggestive of pressure to the optic nerve. The right eye showed impaired upward and medial movement. Magnetic resonance imaging（MRI）showed intraorbital tumor measuring 26 mm×22 mm×21 mm located within the muscle cone. The finding was suggestive of cavernous hemangioma. The tumor was removed after cutting the lacrimal sac which was sewn again after removal. After surgery,binocular single vision improved to 50 degrees. No epiphora was present. Endoscopy one year after surgery showed no stenosis or occlusion of lacrimal sac. Conclusion：Approach through the lacrimal sac resulted in wide operative field and induced no disorder of lacrimal drainage.