Intraosseous meningiomaの1例:文献的考察とそのMRI診断

Report of a case of intraosseous meningioma:a review of the literature and diagnostic value using MRI study

I．はじめに

　頭蓋骨内髄膜腫とはその発生部位あるいは主な腫瘍増殖部位が頭蓋骨内であるものを言い，1932年Atpers^1）以降散発的な文献上の報告をみる．われわれの渉猟した限りわずか36例であった．術前のMRIが診断上有効であったと思われる頭蓋骨内髄膜腫の1例を経験したので若干の文献的考察を加え報告する．

A 40-year-old woman with intraosseous meningioma is reported. She was admitted because of a slowly growing, bony hard, fixed mass in the temporal area that was covered by the normal scalp. The neurological examination on admission was negative. Plain skull radiogram demonstrated an area of hyperostotic change in the temporal region. Bone-targeted CT demonstrated irregularity in the structure of the skull bone. Selective external carotid angiogram showed a homogeneous tumor stain in the region of the skull thickening.

Macroscopically complete tumor resection (Simpson's grade 1) was carried out. Her postoperative course was uneventful. The skull tumor had the typical feature of meningotheliomatous meningioma. MRI showed a mass lesion of the temporal bone on T1-and T2-weighted im-ages, and a well-enhanced mass lesion of the outer dura and outer table of the skull bone on Gd-DTPA en-hanced T1 images. The findings of the preoperative MRI study using Gd-DTPA were identical with the tumor area on histological study. Therefore, MRI with Gd-DTPA enhancement was considered a useful di-agnostic modality.