Primary and secondary tumors of the facial nerve. A temporal bone study.

Of 1400 temporal bones in the collection at the University of Minnesota, Minneapolis, 17 temporal bones from 15 patients were found to have tumors involving the facial nerve. The findings were as follows: one case of facial nerve schwannoma; two cases of invasion of the facial nerve by contiguous tumor; and 14 cases of metastatic tumors involving the facial nerve. Facial nerve paralysis was present in half of the cases (nine of 17). Facial nerve paralysis was present in the case of facial nerve schwannoma, in both cases of invasion of the facial nerve by contiguous tumor, and in six of 14 cases of metastatic tumors involving the facial nerve. The presence of the facial nerve paralysis correlated well with the degree of tumor infiltration into the nerve fibers and the segment of the tumor involvement in the facial nerve. In the patients with metastatic tumors, facial nerve paralysis was a sign of extensive intracranial tumor involvement and was usually accompanied by other cranial nerve palsies, most commonly involving the fifth nerve.