[Intra-labyrinthine Schwannomas: a Report of Two Cases]

Intralabyrinthine schwannomas are rare tumors of vestibule, cochlea, semicircular canals, or some combination of these three. In the past, they have been found at autopsy or as incidental finding at surgery. Since the advent of magnetic resonance imaging (MRI) with intravenous gadolinium contrast, the preoperative diagnosis is possible. We report two cases of intralabyrinthine schwannoma: one case of intralabyrinthine schwannoma extended into the internal auditory canal (IAC), a second case of tumor restricted to the vestibule. No characteristic clinical presentation of this tumor is reported in the literature. In patients with vestibular weakness (vertigo and no response of caloric testing), MRI with gadolinium contrast can make the diagnosis of intravestibular tumor. In patients with the more common IAC acoustic neuromas, MRI can demonstrate extension of tumor into the labyrinth; diagnosing this extension preoperatively is important to plan surgical treatment.