Experience with cerebellopontine angle epidermoids.

Objective: Cerebellopontine angle (CPA) epidermoids, although of benign nature, are of considerable neurosurgical interest because of their close proximity and adherence to the cranial nerves and the brain stem. We describe our experience and attempt to correlate the final outcomes with the extent of surgical removal.

Methods: Twenty-five consecutive patients with CPA epidermoids that were surgically treated were reviewed, and the final outcomes were assessed.

Results: Thirteen patients had trigeminal neuralgia. In 7 of the 13 patients, trigeminal neuralgia was the only presenting feature. The epidermoid was confined to the CPA in each of 6 patients, and in each of 18, it had varying degrees of supratentorial extension. One patient had a predominant supratentorial epidermoid with extension to the CPA. The lesions were totally excised in 12 patients. Near-total removal was accomplished in eight patients, and in the remaining five, partial removal was accomplished. Transient worsening of the cranial nerve functions occurred in 11 patients, probably as a result of aggressive dissection of the capsule from the cranial nerves. In 9 of the 11 patients, the cranial nerve functions improved by the time of discharge. All of the patients who had trigeminal neuralgia were relieved of their symptoms. Eighteen patients were followed up for a mean period of 42 months, and none had symptoms of recurrence.

Conclusion: Aggressive surgical removal results in transient but significant cranial nerve dysfunction in the postoperative period. A conservative approach is indicated for patients in whom the capsule is adherent to the brain stem and the cranial nerves.