片眼が急速に盲となった乳癌の両側眼窩転移の1例

A case of breast cancer metastatic to bilateral orbit resulting in early blindness in one eye

要約　目的：乳癌が両側の眼窩に転移し，片眼が急速に失明した症例の報告。症例：68歳女性が1週間前からの複視で受診した。20年前に乳癌の摘出を受け，5年前に骨，肺，肝に転移があり，加療中であった。所見と経過：矯正視力は右0.8，左0.7で，軽度の白内障以外には両眼とも異常がなく，コンピュータ断層撮影（CT）で眼窩に異常はなかった。3週間後に右眼に深部痛と眼瞼下垂が生じ，右眼視力は零であった。その2週間後の磁気共鳴画像検査（MRI）で視神経から眼窩上縁にかけて腫瘍の浸潤があった。初診から1年後に右前頭葉，側頭葉，左眼眼窩に転移が生じ，その1か月後に不帰の転帰をとった。結論：悪性腫瘍の眼窩転移では，すでに他の臓器に多発していることが多く，治療による予後の改善は期待し難い。しかし，視機能低下を防ぐことは，quality of lifeを維持するために必要である。

Abstract.　Purpose：To report a case of breast cancer metastatic to bilateral orbit resulting in early blindness in one eye. Case：A 68-year-old female presented with diplopia since one week before. She had received resection of breast cancer 20 years before. She had been under treatment for metastasis to the lung,liver and bone since 5 years before. Findings：Corrected visual acuity was 0.8 right and 0.7 left. Routine examinations showed normal findings except incipient cataract in both eyes. Computed tomography showed normal orbits. She developed pain and blepharoptosis in the right eye with visual acuity down to no light perception 3 weeks later. Magnetic resonance imaging（MRI）showed invasion of tumor along the right optic nerve reaching the orbital roof. The tumor metastasized to the left orbit and frontal lobe one year after her initial visit. She passed away one month later. Conclusion：This case illustrates that metastasis of tumor to other organs may be already present when metastasis to the orbit is detected. Treatment of orbital metastasis is necessary in order to preserve the vision and quality of life of the patient.