中枢神経系悪性リンパ腫眼内転移の確定診断に網膜下生検が有用であった1例

A case of central nervous system lymphoma with intraocular metastasis diagnosed by subretinal biopsy

要約　目的：網膜下組織の生検で中枢神経系悪性リンパ腫の眼内転移が確定できた症例の報告。症例：57歳女性が左眼視力低下で受診した。3年前に脳に原発した悪性リンパ腫と診断され，化学療法と放射線治療で寛解した。所見：矯正視力は右1.5，左0.5で，左眼後極部の耳側に融合する網膜下白濁斑があり，これを囲む網膜浮腫と脱色素斑があった。悪性リンパ腫転移の診断的治療としての化学療法で網膜病変は縮小したが再発した。確定診断のために初診から3か月後に硝子体手術を行い，網膜下の標本から異型リンパ球が得られた。免疫染色で脳病変と同様な表現型を示し，悪性リンパ腫の眼内転移と診断した。結論：網膜下細胞診により，悪性リンパ腫眼内転移の診断が確定した。

Abstract.　Purpose：To report a case of central nervous system lymphoma metastatic to the eye definitely diagnosed by subretinal biopsy. Case：A 57-year-old woman presented with failing vision in her left eye. She had been diagnosed with intraocular metastasis diagnosed with primary malignant lymphoma of the central nervous system（CNS）3 years before. It improved after chemotherapy and radiotherapy. Findings：Corrected visual acuity was 1.5 right and 0.5 left. The left eye showed subretinal opaque patches in the temporal sector surrounded by retinal edema and depigmentation. She was treated by chemotherapy to confirm the malignancy. The fundus lesion recurred after temporary improvement. Biopsy by vitrectomy was performed 3 months after her initial visit. The subretinal tissue specimen showed atypical lymphocytes. They showed the same phenotype as those from the brain and led to the diagnosis of intraocular malignant lymphoma. Conclusion：Biopsy of subretinal tissue led to the definite diagnosis of intraocular metastasis of CNS malignant lymphoma.