Abstract
Introduction Vestibular schwannomas are the most common lesions occupying the internal auditory
canal (IAC); however, almost in 4 to 5% of meningiomas, metastases, cysts, lipomas,
and cavernous malformations have been found in this location, mimicking schwannomas.
Even though cerebellopontine angle (CPA) meningiomas with the involvement of the IAC
are frequently encountered, the presence of a primary intracanalicular meningioma
is rare.
Objective To show the technical nuances of the retrosigmoid-transmeatal approach to successfully
achieve gross total resection (GTR) with preservation of facial and auditory function.
Case Report We present a left intracanalicular meningioma on a 60-year-old man with history of
tinnitus and hearing loss. Magnetic resonance imaging (MRI) showed a left intracanalicular
lesion completely obliterating the IAC and with minor extension to the CPA cistern,
with the vestibulocochlear complex dislocated posteriorly, initially diagnosed as
a Hannover's T2 vestibular schwannoma. The patient underwent a left retrosigmoid approach,
and during the exposure of the lesion, the diagnosis of a meningioma became evident.
The transmeatal phase of the approach was modified with a wide opening of the canal,
including the anterior wall. Closure was performed using a muscle graft, duramater
flap, and fibrin glue.
Results GTR was achieved and the patient developed a mild facial palsy (House–Brackmann grade
III) which completely recovered within 3 months.
Conclusions The retrosigmoid transmeatal approach is suitable to achieve GTR in intracanalicular
meningiomas. Some modifications of the approach intended for vestibular schwannomas
are necessary and may be performed during the procedure.
The link to the video can be found at: https://youtu.be/A9OXRFIl1e8.
Keywords
posterior fossa meningioma - retrosigmoid transmeatal approach - intracanalicular
meningioma - cerebellopontine angle tumor
