Solitary intracranial extracerebral glioma.

The authors present the case of a 65-year-old woman with a solitary extracerebral glioma. The tumour originated from the falx in the left fronto-parietal region near the paracentral lobule. Because it was well delineated and was completely outside the brain it was thought at operation to be a meningioma or a metastasis. Histologically the tumour could be classified as an oligodendroglioma (WHO grade II). Intracranial extracerebral gliomas so far described are most frequently located in the vicinity of the sylvian fissure. Involvement of the dura has only been observed in three cases. This case is to the best of our knowledge the only one in which the tumour was situated in the longitudinal fissure having originated from the falx. Extracerebral gliomas are thought to arise from heterotropic nests of glial cells in the leptomeninges.