Facial Nerve Schwannoma Presenting as a Mass in the Middle Cranial Fossa: Typical Neuroradiological Patterns for a Preoperative Diagnosis

Abstract

Facial nerve schwannoma is a rare primary neurogenic tumour that may originate anywhere along the VII^th nerve course. The clinical presentation is highly dependent on the location of the lesion along the nerve course and this makes the pre-operative diagnosis difficult without radiologic examination. The most common presentation is facial palsy and even though tumours are responsible for only 5% of facial palsies, if a patient does not recover within six months a complete work-up for neoplasm is recommended. On the basis of clinical presentation and imaging characteristics radiologists should try to make a preoperative diagnosis, to help in the patient's management and possibly to plan the surgical approach. We describe the case of a successful preoperative diagnosis of facial nerve schwannoma. The aim is to describe the main CT and MRI findings which may help the radiologist to establish a correct differential diagnosis.