Nerve-Sheath-Risen Neuroglial Cyst: A Case Report and Review of the Literature.

BACKGROUND: Neuroglial cysts are rare intracranial lesions that are believed to originate from the sequestration of neural tube lining during embryogenesis. They can present anywhere within the neuraxis; however, their most common location is the frontal lobe. Cerebellopontine angle (CPA) neuroglial cysts are extremely rare and, to the best of our knowledge, there are no previous reports of a neuroglial cyst arising from cranial nerves. CASE DESCRIPTION: The current study presented a male adolescent with the reoccurrence of an intracranial cyst with symptoms of diplopia and facial numbness primarily treated as CPA arachnoid cyst with fenestration of the cyst 12 months prior to admission to our center. Different magnetic resonance imaging sequences showed a thin-walled extra-axial cyst at the right CPA without gadolinium enhancement. Direct visualization of the lesion revealed a cyst arising from the fifth cranial nerve sheath compressing the surrounding structures. The cyst was fenestrated, and a biopsy was taken from the cyst wall. The pathological analysis, along with specified histological markers, indicated the neuroglial nature of the cyst. CONCLUSIONS: The rising of a neuroglial cyst from the nerve sheath is a finding that brings other possible origins of neuroglial cysts into consideration.