印環細胞癌の視神経転移による視神経症

A case of optic neuropathy by signet-ring cell carcinoma metastatic to the optic nerve

要約　目的：胃の印環細胞癌が視神経に転移した症例の報告。症例：63歳男性が10日前からの右眼視力低下で受診した。6か月前に腹痛があり，3か月前に胃癌が発見された。4剤併用による化学療法が行われていた。所見：矯正視力は右手動弁，左1.0であり，右眼に乳頭浮腫と硝子体混濁があった。中心暗点と鼻側視野欠損があった。CTで視神経が芋虫状に腫大し，磁気共鳴画像検査（MRI）で頭蓋内に病的所見はなかった。化学療法の変更で視力は0.3になったが，全身状態が悪化し，播種性血管内凝固症候群が発症し，眼科初診から40日後に不帰の転帰をとった。剖検で胃癌は低分化腺癌非充実型の印環細胞癌であり，右視神経にその浸潤があった。結論：癌の視神経転移が視神経症の原因になることがある。

Abstract.　Purpose：To report a case of metastasis of gastric carcinoma to the optic nerve manifesting as optic neuropathy. Case：A 63-year-old male presented with impaired visual acuity in the right eye since 10 days before. He had had abdominal pain 6 months before and been diagnosed with gastric carcinoma 3 months before. He had been receiving systemic chemotherapy with four drugs. Findings：Corrected visual acuity was hand motion right and 1.0 left. The right eye showed choked disc with vitreous opacity. The right eye showed central scotoma and field defect in the nasal sector. Computed tomography showed spindle-shaped swelling of right optic nerve. No cerebral disorder was detected by magnetic resonance imaging（MRI）. Modification of chemotherapy was followed by improved visual acuity to 0.3. He died of disseminated intravascular coagulation syndrome（DIC）40 days after his initial visit. Conclusions：This case illustrates that optic neuropathy may be caused by metastasis of carcinoma to the optic nerve.