脊髄症にて発症した血栓化を伴わない非出血性頚胸椎移行部硬膜外静脈瘤の1例

A Case of Symptomatic Nonhemorrhagic and Nonthrombotic Cervicothoracic Epidural Varices

Ⅰ．はじめに

　腰仙椎レベルの非出血性脊髄硬膜外静脈瘤による圧迫が原因で神経根症状を来した症例報告や，頚胸椎レベルの脊髄硬膜外静脈瘤が出血や血栓化により神経症状を来した症例報告は散見されるが，頚胸椎レベルで血栓化を伴わない非出血性脊髄硬膜外静脈瘤が神経症状を来した報告は，われわれが渉猟し得た限り過去にはない．

　今回われわれは，脊髄症にて発症した頚胸椎レベルの血栓化を伴わない非出血性脊髄硬膜外静脈瘤の1例を経験したので，文献的考察を加えて報告する．

　We describe an extremely rare case of symptomatic nonhemorrhagic and nonthrombotic cervicothoracic epidural varices. A 45-year-old man presented with back pain and left leg weakness. MRI revealed an epidural mass at the Th1 level, on the dorsal aspect of the spinal canal on the right side. Although MRI scans obtained 10 days after the initial scans（obtained at the first visit to our hospital）revealed disappearance of the epidural mass at the Th1 level on non-contrast images and on images obtained 90 s after intravenous gadolinium injection, the images obtained 5 min after intravenous gadolinium injection revealed the epidural mass at the Th1 level. The patient's symptoms had resolved;therefore, we administered conservative therapy. Although the patient initially continued to show symptomatic improvement, he developed clinical relapse without any evidence of relapse on MRI. Left leg weakness and back pain worsened a year later, and repeat MRI revealed reappearance of the epidural mass at the Th1 level. Cervicothoracic laminectomy revealed nonhemorrhagic epidural varices, and we performed total en bloc resection. Histopathological examination of the resected specimen showed nonthrombotic varices. The patient's neurological symptoms improved postoperatively without relapse. Intermittent expansion of varicose veins in accordance with changes in venous pressure may cause compressive myelopathy. Clinicians should consider the possibility of spinal epidural varices in patients who present with spinal epidural lesions that tend to show intermittent improvement with subsequent worsening.