診断に苦慮した成人悪性視神経膠腫の1例

Diagnostic difficulties in a case of malignant optic nerve glioma of adulthood

要約　目的：成人悪性視神経膠腫の1例の報告。

症例：63歳男性が右眼の急激な視力低下を主訴に受診した。矯正視力は右光覚弁，左0.9であった。激しい視神経乳頭浮腫と網膜出血が認められた。最初の頭部MRIでは視神経腫脹は軽度であり視神経炎の診断であったが，皮下多発腫瘤の生検にてⅠ型神経線維腫症と診断されたため，成人悪性視神経膠腫を疑った。脳外科での視神経の生検で悪性視神経膠腫と診断され，眼球を含めて視神経を摘出した。術後18か月の時点で再発はない。

結論：成人のⅠ型神経線維腫症の患者に激しい視神経乳頭浮腫を認めた場合には悪性視神経膠腫の可能性があり，早急な生検が必要である。

Abstract　Purpose: To report a case of malignant optic nerve glioma of adulthood.

Case: A 63-year-old man presented with sudden visual loss since one week before. Corrected visual acuity was light perception right and 0.9 left. The right eye showed severe optic disc edema and retinal hemorrhage. The findings were suggestive of optic neuritis. MRI showed swelling of right optic nerve, suggesting optic neuritis. Multiple subcutaneous tumors were present in the head. Biopsy led to the diagnosis of neurofibromatosis type 1. The patient was then suspected of malignant optic nerve glioma of adulthood. Intracranial biopsy of optic nerve showed malignant optic nerve glioma. He received surgical removal of right eyeglobe and optic nerve. There has been no recurrence for 18 months until present.

Conclusion: Presence of neurofibromatosis type 1 led to the diagnosis of optic nerve glioma of adulthood in the present case. Early intracranial biopsy was useful in definitive diagnosis.