Pathological findings of the facial nerve in a case of facial nerve palsy associated with benign parotid tumor.

The presence of facial nerve palsy associated with an ipsilateral parotid tumor is virtually pathognomonic for a malignant parotid tumor. However, several case reports have documented the occurrence of facial nerve palsy caused by benign parotid lesions. A case of Warthin's tumor causing facial nerve palsy is presented and discussed histologically. To our knowledge, histological examination of the nerve bundles has never before been reported. The histological findings suggest that ischemia of the nerve caused by external compression resulted in facial nerve palsy.