鞍上部硬膜内脊索腫の1例

A Case of Suprasellar Intradural Chordoma

I．はじめに

　脊索腫は胎生期の脊索遺残組織から発生する腫瘍で，仙尾部および斜台部に好発する．腫瘍は骨破壊を伴って，硬膜外に主座をおき，硬膜内へ浸潤することはあるが，硬膜内に原発することは極めて稀である．鞍上部に発生し，頭蓋咽頭腫と鑑別が困難であった硬膜内脊索腫を経験したので報告する．

An extraosseous and intradural chordoma of the su-prasellar region is described in a 54-year-old male who presented himself with left homonymous hemianopia. Computed tomography showed an isodensity tumor containing a cyst in the suprasellar region. Magnetic re-sonance images demonstrated the tumor as an isoin-tense mass with heterogeneous enhancement after in-travenous administration of a contrast agent, and as a high signal intensity mass on T2-weighted images. The associated cyst was also clearly demonstrated. The tumor was diagnosed preoperatively as a craniopharyn-gioma and was resected using the frontobasal interhe-mispheric approach. However, the resected tumor had the typical histological and immunohistochemical char-acteristics of chordoma.

Only ten cases of totally extraosseous and intradural chordoma have been reported. The histogenetic back-ground of this tumor is also discussed in this paper.