Meningioma within the cisterna magna without dural attachment. Case report.

A case of meningioma within the cisterna magna without dural attachment is reported. Meningiomas of the posterior fossa without dural attachment are very rare and have been classified in to: 1) intraventricular meningiomas; 2) meningiomas of the tela chorioidea; 3) meningiomas within the cisterna magna. Only two cases of meningiomas within the cisterna magna without dural attachment have been reported, one in 1923 and another in 1938. The case now reported was studied by angiography and magnetic resonance and operated with microsurgical technique. We describe neuroradiological and operative findings of this exceptional meningioma within the cisterna magna without dural attachment.