Cavernous Hemangiomas of the Internal Auditory Canal and Cerebellopontine Angle
Outcome Objectives: Review the clinical presentation, differential diagnosis, management strategy and outcomes following microsurgical resection of cavernous hemangiomas (CH) arising primarily within the internal auditory canal (IAC) and cerebellopontine angle (CPA).
Methods: Retrospective review of all patients with histopathologically confirmed CH of the IAC and CPA treated at one of two tertiary academic referral centers. Outcome measures included AAO-HNS hearing class, House-Brackmann (HB) facial nerve (FN) function and tumor control.
Results: Eleven patients (9M:2F; median age 40) were included. The most common presenting symptoms were unilateral sensorineural hearing loss (100%), tinnitus (91%), and vertigo (64%). Nine patients had normal FN function and 2 were found to have serviceable (Class A/B) hearing preoperatively. Eight patients were diagnosed preoperatively as vestibular schwannoma (VS). All patients underwent MRI scan prior to surgical intervention. Five patients had imaging available for analysis. Four patients showed an isointense lesion on T1 (80%), all lesions were hyperintense on T2 imaging (100%) and all showed heterogeneous enhancement with gadolinium administration (100%). The median tumor diameter was 8 mm. Seven CH were confined to the IAC while four involved the CPA. Surgical approaches included 7 translabyrinthine, 3 retrosigmoid, and 1 middle cranial fossa. Ten patients received gross total resection, while 1 underwent subtotal removal. Neither patient with serviceable preoperative hearing retained useful postoperative hearing. One patient experienced long term postoperative FN paresis, and no recurrences were diagnosed after a median follow-up of 9 months (range:0–71).
Conclusions: Primary CH of the IAC and CPA are rare and present similarly to VS. Symptoms may be disproportionate to tumor size, therefore early intervention should be considered. Microsurgical resection may provide excellent FN outcomes and tumor control, while most patients will acquire ipsilateral non-serviceable hearing either from disease or as a result of treatment.
|Patient Number||Age||Presenting symptom||Pre-Operative Diagnosis||Pre-Operative Hearing Classification||Post-Operative Hearing Classification||Pre-Operative FN Function||Post-Operative FN Function|