骨硬化性変化を呈した仙骨脊索腫の1例

A case of sclerotic sacral chordoma

脊索腫（chordoma）は脊索の遺残に由来すると考えられている悪性腫瘍であり，同じく脊索細胞由来の良性腫瘍である良性脊索細胞腫（benign notochordal cell tumor：BNCT）とは，造影効果や軟部組織病変，骨硬化性変化の有無で鑑別可能とされている^1）2）。今回我々は，造影効果が乏しく，骨硬化性変化を伴い，良性脊索細胞腫との鑑別を要した脊索腫の症例を経験したため，文献的考察を加えて報告する。

An 84-year-old man presented with pain and numbness in the right lower extremity. CT revealed a sclerosing sacral tumor forming a soft tissue mass. MRI showed hyperintensity on T2 weighted image and poor contrast-enhancement. After biopsy, the tumor was diagnosed as chordoma. Occasionally chordoma and benign notochordal cell tumor（BNCT）are difficult to differentiate because the imaging findings of chordoma and BNCT overlap. Chordoma could be diagnosed from the formation of a large soft tissue mass.