視交叉部および周辺に肥厚性硬膜炎を認めた1例

A case of hypertrophic pachymeningitis around the optic chiasm

（P-1-84）　62歳男性が左眼視力低下で受診し，その翌日に右眼霧視が生じた。2年前に両側の末梢性顔面神経麻痺を発症し，ステロイド投与で軽快している。矯正視力は右1.0，左0.01であり，左眼視野の高度狭窄があった。ガドリニウム増強磁気共鴫画像検査（MRl）で視神経，視交叉，下垂体が強く造影され，斜台硬膜に肥厚があった。血中のアンギオテンシン交換酵素が高値を示した。サルコイドーシスと診断し，副腎皮質ステロイドの全身投与で3週後に視力と視野は改善した。6か月後に左眼視朦が再発した。開頭手術で，視神経周囲の肥厚した硬膜を剥離した。ステロイド投与を併用し，左眼視力は正常化した。摘出硬膜は線維性に肥厚し，慢性非特異的炎症細胞の浸潤があった。サルコイドーシスに続発した頭蓋底部の肥厚性硬膜炎と診断した。

A 62-year-old male developed bilateral blurring of vision. He had been successfully treated for bilateral facial palsy 2 years before with systemic corticosteroid. His corrected visual acuity was 1.0 right and 0.01 left. His left visual field was severely constricted. Gadolinium-enhanced magnetic resonance imaging (MRI) showed intense signals around the optic tracts, optic chiasm and the pituitary gland. The clivus was also thickened. Serum studies showed enhanced level of angiotensin-converting enzyme (ACE) . Systemic corticosteroid induced improvement in visual acuity and field 3 weeks later. Blurring of vision in his left eye recurred 6 months later. He underwent surgery to remove the thickened dura mater around the optic chiasm. Additional corticosteroid therapy induced normal visual acuity. The removed dura mater showed fibrous thickening with infiltration of chronic nonspecific inflammatory cells. He was diagnosed as hypertrophic pachymengitis secondary to sarcoidosis.