Spontaneous Medial Migration of an Intracanalicular Vestibular Schwannoma

The localization and growth pattern of vestibular schwannomas correlate with their clinical impact. These tumors may present with neurologic deficits, such as hearing loss, or may be detected incidentally. Advances in imaging allow detection and close monitoring of smaller lesions confined within the internal acoustic canal (IAC). These tumors generally remain stable in size or grow slowly. As such, while they may be treated proactively, a watchful observation approach is also acceptable for stable tumors.

Among lesions that grow, medial extension toward the porus and cerebellopontine angle (CPA) is most frequently observed. However, migration of the entire tumor is extremely rare with only two cases of medial movement previously reported. Here, we present the case of a slowly growing intracanalicular VS which was found to migrate medially in the IAC over 4 years. The patient originally presented with hearing loss but has had stable neurological deficits throughout the observation period.