chordoid Meningiomaの1例

A Case of Chordoid Meningioma

I．はじめに

　Chordoid meningiomaは，1988年にKepes^9）らによって提唱され，1993年のWHO新分類でme-ningiomaの一亜型として分類されたchordomaに類似した特徴を持ったmeningiomaである．その大部分は小児例であるが，未だ文献報告は数少ない^{2,7,9-11,13）}．今回われわれはchordoid menin-giomaの成人例を経験したので，若干の文献的考察を加えて報告する．

Chordoid meningioma is a very rare variant, especially in adults. We report an adult case of chordoidmeningioma.

A 52-year-old man was admitted to our hospital due to right hemiparesis. MRI revealed a left temporalconvexity mass that showed two structures; the cerebral layer was shown as an isointensity area on T1WIand T2WI, and the dural layer seemed relatively hypointense on T1WI and hyperintense on T2WI. Thetumor was well enhanced with gadolinium, especially on the dural side. A left external carotid arteriogramshowed tumor stains with feeding vessels from the left middle meningeal artery. The tumor was totallyremoved via fronto-temporal craniotomy. Histological examination of the surgical specimen revealed two different structural components, menin-gothelial meningioma on the cerebral side, and chordoid meningioma on the dural side, consisting of clus-tering spindled cells and partly vacuolated ones in the mucoid stroma. In immunohistochemical examina-tion, tumor cells showed positive staining for vimentin and epithelial membrane antigen (EMA), and nega-tive for cytokeratin.

From the above findings, this case was diagnosed as chordoid meningioma in an adult, a very rare vari-ant of meningioma.