A rare case of malignant glioma suspected to have arisen from a cavernous sinus.

A 55-year-old woman presented with a right trigeminal dysfunction (dysesthesia) initially, followed by right oculomotor and abducens paresis lasting 1 month. Neuroimaging studies showed an enhanced mass in the right cavernous sinus extending to the trigeminal ganglion. The extraparenchymal tumor located around the right trigeminal ganglion was totally removed, except for an intracavernous lesion, by the orbitozygomatic approach. The solid tumor was completely separated from the brainstem and seemed to be a trigeminal schwannoma arising from the trigeminal ganglion or cavernous sinus at surgery. A histological examination, however, found a typical malignant glioma that consisted primarily of astrocytic tumor cells. Immunohistochemical staining showed the tumor cells stained intensely for GFAP, S-100 protein, and vimentin, but not for NFP, Schwann/2E, CD34, and CD68. The mean MIB-1 index was 12.4%. The tumor recurred after a short time, and then it rapidly disseminated into the subarachnoid space and left the cerebral hemisphere. The patient died 1 year after the initial symptoms in spite of aggressive surgery, radiation, and chemotherapy with temozolomide. There are no previous reports of a malignant glioma arising from either the cavernous sinus or the trigeminal ganglion. From the pathogenetic point of view, this malignant glioma is an extremely rare case that developed clinically and neuroradiologically from the cavernous sinus and was suspected be being derived from ectopic glial tissue.