A vestibular schwannoma (also known as acoustic neuroma, acoustic neurinoma, or acoustic neurilemoma) is a benign, usually slow-growing cerebellopontine angle tumor that develops from the balance and hearing nerves supplying the inner ear. The tumor comes from an overproduction of Schwann cells.
Gao S et al., reported a cerebellar glioblastoma multiforme patient, with his clinical presentations and imaging characteristics mimicking a vestibular schwannoma. To the best of authors knowledge, this is the first reported patient with cGBM mimicking a vestibular schwannoma 1).
A young man with cystic fibrosis in his early 30s presented to accident and emergency with acute onset unilateral lower motor neuron facial palsy, hearing loss and impaired balance following Mycobacterium abscessus eradication induction therapy. The hearing loss and impaired balance developed over a 3-day period prior to the onset of facial palsy. Further investigation with a CT scan and MRI scan led to a diagnosis of vestibular schwannoma. The facial palsy resolved with steroid treatment; however, the hearing loss is irreversible, which has had a profound impact on his life and career. This case is intriguing as the cause and association of events are unclear. A working diagnosis of incidental Bell's palsy and unilateral hearing loss caused by the vestibular schwannoma was applied. However, the onset of these symptoms in relation to M. abscessus eradication induction therapy promotes discussion 2).
Kritikos et al. encountered a case of DAVF associated with an octreotide-positive vestibular schwannoma. A 46-year-old female had symptoms of right ear congestion accompanied by pulsatile tinnitus and mild hearing loss. Magnetic resonance imaging (MRI) identified a lobulated mass centered at the cerebellopontine angle. Preoperatively, on cerebral angiography, there was an incidental discovery of a DAVF in the right posterior fossa. The decision was made to proceed with resection of the tumor in a staged fashion. Her latest follow-up MRI showed no evidence of recurrent tumor. This is the second reported case of DAVF associated with an intracranial schwannoma. Findings are discussed along with a thorough review of the literature. This case, combined with the data from the literature review, led us to believe that tumor-related angiogenesis might contribute to DAVF formation 3).
Temporal bone invasion by VS is extremely rare. A 51-year-old man who revealed temporal bone destruction beyond IAC by unilateral VS. The bony destruction extended anteriorly to the carotid canal and inferiorly to the jugular foramen. On histopathologic examination, the tumor showed typical benign schwannoma and did not show any unusual vascularity or malignant feature. Facial nerve was severely compressed and distorted by tumor, which unevenly eroded temporal bone in surgical field. Vestibular schwannoma with atypical invasion of temporal bone can be successfully treated with combined translabyrinthine and lateral suboccipiral approach without facial nerve dysfunction. Early detection and careful dissection of facial nerve with intraoperative monitoring should be considered during operation due to severe adhesion and distortion of facial nerve by tumor and eroded temporal bone 4)
A 15-year-old male who presented with hearing loss due to a small left-sided vestibular schwannoma (VS) not associated with neurofibromatosis type 2 (NF2), which had been apparent for six months. Magnetic resonance imaging with gadolinium diethylenetriamine penta-acetic acid revealed a mass, 10 mm in diameter, located in the left inner auditory canal. The patient had no family history of NF2 and gene mutation analysis showed no signs of the condition. Small sporadic or non-NF2 VS is extremely rare and the treatment decision-making process is complicated in children when considering the implications for the impairment of childhood development and lifelong disability. Following careful consideration, the patient in the present study underwent treatment with stereotactic radiosurgery. The five-year post-operative follow-up examination showed tumor stability without additional neurological deficits and at the time of writing the patient was alive and well 5).