大脳鎌から発生した軟骨腫の1例

A Case Report of the Chondroma Arising from the Falx Cerebri

Ⅰ．はじめに

　頭蓋内軟骨腫は，全頭蓋内腫瘍のうち0.2～0.3％を占める稀なものである．そのうち，頭蓋底部に発生するものが多くを占め，硬膜より発生するものは極めて稀である．特に，大脳鎌から発生した頭蓋内軟骨腫は，現在までに英文報告の15例のみであり，邦文の報告はわれわれが渉猟し得た限りでは存在しなかった．今回われわれは，この極めて稀な1例を報告し，その特徴や鑑別診断の要点につき考察を加える．

We have reported a case of chondroma arising from the falx cerebri in a 60-year-old female with no neurological symptom. The tumor was revealed as a round mass,attached to the falx cerebri ,with marginally scattered calcification on CT scan and with slight enhancement on MRI images. And cerebral angiogram presented a mass with no tumor stain on the external carotid angiography against our preoperative diagnosis of falx meningioma. A subtotal removal of the mass was performed with the diagnosis of chondroma on pathological examination.

　The chondroma arising from the falx cerebri is extremely rare with only 15 reported cases in the literature. We have presented the first case in Japan and reviewed the previous reports.