An atypical case of intracerebral schwannoma

Abstract

We report a case of intracerebral cystic schwannoma in the temporal fossa manifested as a gradually worsening headache in a 49-years-old woman. Computed Tomography (CT) and magnetic resonance imaging (MRI) showed a left temporal partly cystic, partly solid mass. The preoperative diagnosis was astrocytoma or glioblastoma multiforme (GBM), but microscopic examination of the mass showed the characteristic pattern with cellular Antony A component. Immunohistochemically, the tumor was positive for S-100 protein. These findings are consistent with a schwannoma. Intracerebral schwannomas not related to cranial nerves are rare and most reported cases involved young patients.

Fractionated Radiosurgical Treatment of Intracerebral Schwannoma: A Case Report and Literature Review

“…9,10 Another theory is that multipotent mesenchymal ancestor cells can spontaneously differentiate into Schwann cells. [9][10][11][12][13][14] Congenital hamartomas may also represent a potential origin, explaining predominance of younger patients. 10 In comparison to cranial nerve schwannoma, ICS usually has special radiological findings: varying degrees of contrast enhancement of the solid tumor component, more common calcification, cyst formation, and perifocal edema.…”

“…The specimens should be examined applying immunohistochemistry to make a correct diagnosis. 10,13,22 Schwannomas are diffusely positive for S100 protein, multifocally positive for CD34, variably positive for glial fibrillary acidic protein (GFAP), and uniformly negative for EMA. 10 Stereotactic radiosurgery (SRS) is a well established option for treatment of vestibular and, in rarer cases, nonvestibular schwannomas originating from other cranial nerves.…”

“…12 Intracerebral schwannomas have been reported most commonly in the frontal, parietal, and occipital lobes and typically present with headache, signs of increased intracranial pressure, or focal seizures related to localization of tumor. 10,13,14 More than 85% of ICS are supratentorial, showing a predilection for periventricular or superficial localization. 15 Preoperative differential diagnoses include pilocytic astrocytoma, pleomorphic xanthoastrocytoma, ganglioglioma, meningioma, and glioblastoma.…”