Facial palsy caused by an intrameatal metastatic disease - Reconstruction with an autologous sural nerve graft

Dysfunction of the facial nerve is frequently attributed to inflammation, followed by traumatic injury. Knowledge of the complex anatomical course of the facial nerve is critical to localize the site of pathology and for successful management. The multiplicity of etiologies and its complex anatomy often make facial paralysis a diagnostic challenge. Neoplasms are a fairly rare cause of peripheral facial palsy, and are frequently overlooked in search of the more frequent traumatic or inflammatory etiologies of facial paralysis. Isolated metastatic lesions to the cerebellopontine angle (CPA) and internal auditory canal (IAC) are extremely rare. Their accurate diagnosis is difficult, since they share common clinical and radiological characteristics with vestibular schwannomas. We report a case of a 63-year-old female with a rapidly progressive left-sided hearing loss and complete facial palsy. Magnetic resonance imaging revealed a left intrameatal lesion. A provisional diagnosis of intracanalicular schwannoma or meningioma was made, although the possibility of metastasis due to her rapid neurological deterioration was considered. The patient underwent a translabyrinthine complete removal of the tumor followed by facial nerve reconstruction. The final histopathological findings revealed a metastatic breast adenocarcinoma. To our knowledge only seven prior cases of an isolated metastatic CPA lesion have been reported. In patients without a known malignancy, a rapid progression of hearing loss, disequilibrium, and facial palsy might be the first sign of a metastatic CPA lesion.