Regional spread of nonneurogenic tumors to the skull base via the facial nerve.
Overview
abstract
OBJECTIVE: This study examined the clinical and pathologic features of regional spread of nonneurogenic neoplastic disease to the intratemporal segments of the facial nerve. STUDY DESIGN: Retrospective review.SETTING Three tertiary referral centers. PATIENTS: Six patients with neoplastic disease of nonneurogenic origin involving segments of the facial nerve within the temporal bone. INTERVENTIONS: All patients underwent surgery with curative intent. Five patients received adjuvant radiation, and two received adjuvant radiation and chemotherapy. MAIN OUTCOME MEASURES: Histopathology, site of primary tumor, intratemporal location of regional spread along the facial nerve, degree of facial paralysis, and presence of residual disease. RESULTS: Five cases of malignancy were reported: one case of parotid adenoid cystic carcinoma, one case of parotid mucoepidermoid carcinoma, two cases of squamous cell carcinoma of the skin, and one case of an unidentified carcinoma. Perineural spread was histologically found in all cases of malignant disease. In addition, one case of benign pleomorphic adenoma of the parotid gland that circumferentially involved an intratemporal segment of the facial nerve was reported. Facial paralysis was present in five of six (83%) of cases. Four patients had unresectable malignant disease, and two died despite multimodality therapy. CONCLUSIONS: The facial nerve provides a route for the spread of neoplastic disease into the temporal bone, and perineural invasion is an important mechanism of invasion and motility of malignant disease. Nonneurogenic intratemporal tumors of the facial nerve are a rare but significant cause of facial paralysis.
