急性骨髄性白血病寛解期に再発を繰り返した浸潤性視神経症の1例

A case of acute myelogenous leukemia with recurrence of infiltative optic neuropathy during remissions

要約　目的：急性骨髄性白血病の視神経浸潤が，白血病の寛解期に再発を繰り返した症例の報告。

症例：64歳男性が1か月前からの左眼視力低下で受診した。約4年前に急性骨髄性白血病が発症し，化学療法で寛解していた。

所見と経過：視力は右0.3，左手動弁で，両眼の乳頭に軽度の発赤があった。髄液検査で細胞数が増加し，白血病細胞があり，白血病視神経浸潤と診断した。ステロイドパルス療法と抗癌剤の髄腔注入で眼所見は改善したが，以後6か月間に3回の再発があり，加療を繰り返した。初診から8か月後に両眼に乳頭浮腫が生じ，MRIで視神経の腫大があった。放射線照射で視力は維持された。その2年後に再発があり，放射線照射で視力が維持された。2か月後に全身状態が悪化し，不帰の転帰をとった。

結論：急性骨髄性白血病の視神経浸潤の症例で，早期診断と治療により，比較的長期間の視機能が保持された。

Abstract　Purpose: To report a case of acute myelogenous leukemia with recurrence of infiltative optic neuropathy during remissions.

Case: A 64-year-old male presented with impaired visual acuity in the left eye since one month before. He had been diagnosed with acute myelogenous leukemia about 4 years before and successfully treated by chemotherapy.

Findings and Clinical Course: Corrected visual acuity was 0.3 right and hand movement left. Both eyes showed mild hyperemia of optic disc. The spinal fluid showed pleocytosis and leukemic cells, leading to the diagnosis of optic nerve infiltration by leukemic cells. Visual acuity improved after pulsed steroid therapy and intrathecal chemotherapy. Ocular manifestations recurred 3 times during the ensuing 6 months that responded to treatments. Severe optic disc edema developed in both eyes 8 months after his initial visit. MRI showed swelling of optic nerves. Visual acuity was maintained with no recurrence for 2 years after topical radiation.

Conclusion: The present case illustrates that visual function may be maintained after early diagnosis and treatment of infiltrative optic neuropathy in acute myelogenous leukemia.