Facial palsy: unusual etiology.

This is a report of three patients who presented at the Mayo Clinic over a two-year period. All were initially diagnosed as having Bell's palsy but were later found to have a malignant neoplasm causing the paralysis. Two of the patients had breast carcinoma metastases involving the mastoid portion of the facial nerve. The third patient had an adenocarcinoma of the deep lobe of the parotid that involved the facial nerve distal to the stylomastoid foramen. The course of the facial paralysis in the two patients with the metastitic breast disease was almost identical. It consisted of episodes of pain in the mastoid area. generally in the late evening or during the night, often awakening the patient from sleep. This was then followed by peripheral facial-nerve paralysis, sometimes partial and at other times complete. These episodes lasted from 10 minutes to several hours and then resolved completely. They recurred over several months. The patients were completely asymptomatic and normal on examination in the intervals between episodes of paralysis until it became permanent. Metastatic lesions causing facial paralysis are extremely rare in the literature. In those cases that have been reported, the paralysis was progressive from the start and in the vast majority of cases was either painless or associated with other aural symptoms such as otorrhea, hearing loss, and periauricular swelling. There are two unusual features of these two cases: 1. the initial presentation of a breast metastasis as a facial paralysis; in the first case there were no other metastatic lesions present at diagnosis, whereas the second patient had other, asymptomatic, metastatic nodules; and 2. the multiple, brief, recurring episodes of facial paralysis, which have not previously been reported as a mode of presentation of metastitic disease. The third patient was diagnosed as having Bell's palsy. A facial nerve decompression was performed, and the nerve apparently looked normal. The paralysis failed to resolve. He was later found to have adenocarcinoma of the deep lobe of the parotid that involved the facial nerve distal to the stylomastoid foramen. A report of only one similar case could be found in the literature. The sequence of events in these three cases emphasizes the importance of submitting a patient suspected of having Bell's palsy to a thorough otoneurologic examination.