Epidermoid tumors of Meckel's cave: case report and review of the literature.

Lesions of Meckel's cave are extremely uncommon and difficult to diagnose. The symptoms and signs are variable, and the lesions may not appear on routine roentgenographic or computed tomographic examination. A patient with a small epidermoid tumor of Meckel's cave that was diagnosed by magnetic resonance imaging is herein reported. The epidermoid appeared as a low-intensity mass on the T1-weighted image and as a high-intensity mass on the T2-weighted image. Coronal sections defined the anatomic relationship to the trigeminal nerve. Preoperative recordings of the trigeminal sensory evoked response may be predictive of postoperative recovery of neurological deficits. Furthermore, intraoperative recording was extremely useful in avoiding inadvertent neurological injury. Review of the literature confirms the rarity of this lesion and the usefulness of magnetic resonance imaging in diagnosing it, although based on a limited number of cases.