Unusual Intracerebral Presentation of a Myxoid Neurofibroma.

Abstract

Neurofibromas are benign nerve sheath tumors that usually affect peripheral nerves and are related to neurofibromatosis type 1; however, they have not been described as a cause of intraparenchymal brain tumor. We report a case of intracranial myxoid neurofibroma in a 19-year-old female patient manifested as an intense and progressive cephalea, followed by nausea, vomiting, photophobia, and phonophobia. Computed tomography and magnetic resonance imaging showed an extant, expansive left frontoparietal parafalcine/parasagittal tumor. Histopathologic examination determined S-100 protein and CD34 positivity, as well as sparse expression of Ki67 protein, and indicated Schwann cells with characteristic wavy nuclei and intraneural fibroblasts in a myxoid background. Together, these observations characterized the tumor as myxoid neurofibroma. The tumor was excised, and the patient recovered without deficits and with no signs of recurrence after 6 years of follow-up. This is a novel presentation of a myxoid neurofibroma. The tumorigenesis mechanisms are likely complex and possibly involve the differentiation of Schwann cells present in adrenergic autonomic nerves in the subarachnoid arterial branches or in trigeminal nerves present in the meningeal convexity.