Hemorrhagic Vestibular Schwannoma: Case Report and Literature Review of Incidence and Risk Factors

Vestibular Schwannoma Leading to Contacting Aneurysm Rupture: An Unusual Presentation

Subarachnoid hemorrhage (SAH) is a rare manifestation of brain tumors, being even rarer in vestibular schwannomas. We report the second case of a posterior circulation aneurysm close to the tumor capsule, responsible for SAH as an initial manifestation of a vestibular schwannoma. A 67-year-old female was admitted to the Emergency Department with sudden onset of nausea and headache. A diagnosis of a SAH and a tumor of the right cerebellopontine angle was made. An angiography showed an aneurysm in the dependency of the right anterior inferior cerebellar artery (AICA), juxtaposed to the tumor capsule. The patient underwent surgery, the tumor was removed, and the aneurysm was treated. This case highlights that SAH in patients with vestibular schwannoma may originate from a contact aneurysm. Although exceedingly rare, surgeons should consider this scenario in vestibular schwannoma presenting with SAH, and angiography is important for its diagnosis.

Let Us Not Forget About Bleeding: A Case Report and Brief Literature Review on Hemorrhagic Vestibular Schwannoma

Hemorrhagic vestibular schwannoma (HVS) consisting of acute intratumoral and subarachnoid hemorrhage is a rare phenomenon. We present the case of a 31-year-old woman who attended the Otorhinolaryngology department with right-sided intense tinnitus, dizziness, imbalance, and headache. Brain computed tomography revealed a spontaneous hyperdensity in the posterior fossa with marked deformation of the brainstem, middle cerebral peduncle, and cerebellum, with the near collapse of the fourth ventricle. Ophthalmology evaluation confirmed bilateral papilledema. Brain magnetic resonance imaging confirmed a voluminous 33 x 28 x 29 mm extra-axial lesion centered on the right pontine-cerebellar angle cistern, extending from the plane of the trigeminal nerve/tent of the cerebellum. The acoustic pore was enlarged. The patient underwent retrosigmoid craniotomy and microscopic tumor resection showing significant improvement in the follow-up. Pathological findings confirmed HVS. Delayed treatment of HVS can increase morbidity or even be fatal. The objective of this work is to describe and revise HVS, in order to bring awareness to this uncommon entity.

Hypervascular vestibular schwannoma: A case report and review of the literature

Vestibular schwannomas, also known as acoustic neuromas, are benign tumors that arise from Schwann cells near the transition from glial cells to Schwann cells. While most vestibular schwannomas are hypovascular tumors, a small percentage constitute the hemorrhagic and/or hypervascular vestibular schwannomas (HVS) subtype. We describe a case of a 36-year-old female who presented with nausea, vomiting, and an acute decrease in vision in her right eye. Computed tomography of the head demonstrated a hemorrhagic lesion in the right hemisphere with evidence of ventricular effacement. Follow-up magnetic resonance imaging revealed a mass in the right cerebellopontine angle that was hypointense on T1-weighted imaging and mild hyperintense heterogeneous signal on T2-weighted imaging, suggestive of a hemorrhagic vestibular schwannoma. It is important for radiologists to recognize the unique clinical and radiological features of HVS in the initial diagnostic assessment of cerebellopontine angle tumors and to distinguish it from common (hypovascular) vestibular schwannomas and other related pathologies. A preoperative diagnosis of HVS allows clinicians to become familiar with the unique characteristics of the tumor and to devise a feasible operative strategy prior to surgical resection.