急性前骨髄性白血病の寛解導入療法中に発症した浸潤性視神経症の1例

Infiltrative optic neuropathy in a case of acute promyelocytic leukemia during remission induction therapy

　14歳女性が急性前骨髄性白血病と診断され，寛解期導入療法を受けて血液学的に良好な経過をとっていた。治療開始から17日目に左眼視力が低下し，両眼の白血病網膜症と診断した。その後，両眼の視神経乳頭腫脹と左眼の網膜剥離が発症した。MRI検査で視神経腫大と視神経周囲の高信号があり，限界フリッカ値低下があった。これらから浸潤性視神経症と診断した。髄液検査で白血病細胞はなかったが，抗癌剤の点滴静注，髄腔内注入と放射線照射を行い，眼所見は改善した。白血病では良好な血液学的経過にかかわらず重篤な視神経症が生じることを示す例である。

A 14-year-old girl had been diagnosed as acute promyelocytic leukemia followed by remission induction chemotherapy resulting in hematological improvement. She noted visual failure in her left eye 17 days after initiation of therapy. Both eyes showed leukemic retinopathy. She later manifested bilateral swelling of optic nerve head and retinal detachment in the left eye. Magnetic resonance imaging showed swelling of the optic nerve and high-intensity signal around the optic disc. Critical flicker fusion was reduced. These findings led the diagnosis of infiltrative optic neuropathy. No leukemic cells were detected in the cerebrospinal fluid. Her eye findings improved after intravenous and intrachecal chemotherapy followed by radiation to the posterior eye segment. This case illustrates that severe optic neuropathy may manifest in leukemia with apparently improved hematological findings.