Intracranial Malignant Nerve Sheath Tumor in the Middle Cranial Fossa: A Rare Case Report with Review of Literature

Intracranial malignant nerve sheath tumors rarely arise in the central nervous system. They usually arise from the cranial nerves, though rare cases of intraparenchymal lesions have also been reported. We report a case of malignant nerve sheath tumor located in the right middle cranial fossa. Preoperatively, the lesion resembled a meningioma arising from the petrous temporal bone. The lesion was completely excised. Postoperatively, the patient developed righted-sided complete facial nerve palsy. Histopathology and immunohistochemistry revealed the lesion to be a malignant nerve sheath tumor. The development of postoperative facial nerve palsy was puzzling but could be explained if we consider the possibility of the lesion arising from the facial nerve near the geniculate ganglion. Intracranial malignant nerve sheath tumor centered over the geniculate ganglion and projecting into the middle cranial fossa is uncommon, and to the best of our knowledge, only one such case has been previously reported. We review the relevant literature, discuss the management and add to the previously reported cases of this rare condition.