Intracanalicular meningioma: Clinical features, radiologic findings, and surgical management

Objective: Intracanalicular meningiomas are extremely rare, and only 36 cases have been reported to date. The aim of this study is to describe the clinical, radiologic, and histopathologic features of 13 intracanalicular meningiomas highlighting important aspects of tumor diagnosis and treatment. Study Design: Retrospective study. Setting: Quaternary referral otology and cranial base private center. Patients: Thirteen consecutive patients with pathologically confirmed intracanalicular meningioma surgically treated between December 1988 and July 2006. The follow-up of the series ranged from 13 to 60 months. Interventions: Nine patients with unserviceable hearing were operated on through the transtabyrinthine approach. Four patients underwent enlarged middle cranial fossa approach with the intention of preserving their hearing. Results: Total tumor removal was achieved in all cases. The postoperative facial nerve function was either excellent or good (House-Brackmann Grade I or II) in 10 cases (77%) and acceptable (Grade III) in one case. Two patients with preoperative facial paresis showed no improvement in their facial nerve function. In patients who underwent surgery via the enlarged middle cranial fossa, hearing was preserved at the preoperative level in two cases, but serviceable hearing was lost in the remaining two. Conclusion: Primary meningiomas of the internal auditory canal are extremely rare. On account of a lack of specific symptoms and the limited diagnostic findings, preoperative diagnosis of intracanalicular meningioma still represents a diagnostic challenge. Intraoperative findings may help in differentiating meningiomas from other intracanalicular lesions.