両眼急速に盲となった胃癌による髄膜癌腫症の1例

A case of gastric carcinoma metastatic to the leptomeninx resulting in rapid blindness

要約　目的：胃癌が転移して髄膜癌腫症になり，急速に失明した症例の報告。症例：58歳男性が1週間前からの複視で受診した。2年前にスキルス胃癌と診断され，胃全摘を受け，抗癌薬で治療中であった。所見：矯正視力は左右とも1.2で，眼底に異常所見はなく，左眼に外転障害があった。初診から17日後に午後の仮眠後に視力低下を自覚した。視力は左右とも10cm指数弁で，磁気共鳴画像検査（MRI）で視神経周囲の浸潤と，髄膜癌腫症を示唆する所見があった。髄液圧亢進があり，2か月後に不帰の転機をとった。結論：眼底は正常所見であったが，胃癌から転移性髄膜癌腫症になり，これが視力障害の原因であると推定される。

Abstract.　Purpose：To report a case of acute blindness secondary to leptomeningeal carcimatosis metastatic from gastric carcinoma. Case：A 58-year-old male presented with diplopia since one week before. He had been diagnosed with gastric carcinoma 2 years before. He had been treated by systemic chemotherapy following total resection of the stomach. Findings：Corrected visual acuity was 1.2 in either eye. Fundus findings were inconspicuous. The left eye showed limited abduction. He noticed visual impairment following afternoon nap 17 days after his initial visit. Visual acuity was hand motion/10 cm in either eye. Magnetic resonance imaging（MRI）showed infiltration around the optic nerve and findings suggestive of leptomeningeal carcinomatosis. The cerebrospinal fluid pressure was elevated. He passed away 2 months later. Conclusion：While the fundus appeared to be normal in this patient,gastric carcinoma appears to have induced metastatic leptomeningitis leading to rapid blindness.