Middle Fossa Meningioma Mimicking Facial Nerve Schwannoma—Case Report

Introduction: Meningiomas are the most common skull base tumors and have several patterns of location and presentation. Facial nerve schwannomas are rare lesions, corresponding to 1.9% of all intracranial neoplasms and 0.9% of intrapetrous tumors. Their most common symptoms are peripheric facial palsy (63.2%) and hearing loss (50.6%).

Case Description: We report the case of a 55-year-old female patient with a history of acute left facial palsy 17 years ago, with no signs of recovery. On admission, she presented with left peripheric VII CN palsy (House-Brackmann 6) and left-ear hearing loss. Audiometry showed left-ear moderate conductive loss. MRI showed left temporal lesion (geniculate ganglion topography), with caudal extension to the middle ear and ventral extension to the petrous portion of the left carotid artery (great petrosal superficial nerve topography). It was hyperintense on T2-weighted images and had significant enhancement after gadolinium injection. The main neuroradiological hypothesis was a facial nerve schwannoma. Surgical treatment was performed through a subtemporal approach, and the perioperative lesion aspect showed dural infiltration and bone destruction of petrous bone through the middle ear. Histopathological analysis revealed meningioma, and postoperative MRI showed complete resection (Simpson I) of the tumor. The patient had slight improvement of the auditory deficit but no improvement of facial palsy.

Conclusion: Although meningiomas and facial nerve schwannomas are differential diagnoses, clinical and radiological presentation may lead to an unequivocal hypothesis. We report an unusual and rare case, which reminds that skull base tumors are complex due to their location; therefore, we may face atypical presentations of common tumors, making histopathological analysis even more relevant for decision making.