Cerebellopontine Angle Anaplastic Ganglioglioma Masquerading as Vestibular Schwannoma: Unusual Entity

Abstract

Anaplastic gangliogliomas at the cerebellopontine angle (CPA) are exceptionally rare with only a few reported cases in published literature. These are composed of atypical ganglion cells and astrocytes accounting for nearly 1% of all central nervous system tumors. The authors report the case of anaplastic ganglioglioma in an adult patient presenting as a CPA mass lesion. The presentation was bizarre, and the diagnosis was possible only after histopathologic examination of the resected mass. A 32-year-old lady presented with complaints of gradually progressive hearing loss and tinnitus in her right ear along with headache and ataxia. Neurologic evaluation revealed right-sided sensorineural hearing loss and truncal ataxia. Magnetic resonance imaging of the brain was suggestive of a well-defined, contrast-enhancing, solid-cystic mass at the CPA cistern that extended into the porus acusticus, causing enlargement of the internal acoustic meatus. The features were suggestive of vestibular schwannoma of the CPA. This unusual appearance of anaplastic ganglioglioma has not been previously described. Neurosurgeons need to keep in mind the possibility of anaplastic gangliogliomas in the differential diagnosis of CPA lesions.