[Intralabyrinthine schwannomas : Surgical management and hearing rehabilitation with cochlear implants. German...

Intralabyrinthine schwannomas (ILS) are a rare differential diagnosis of sudden hearing loss and vertigo. In an own case series of 12 patients, 6 tumors showed an intracochlear, 3 an intravestibular, 1 a transmodiolar including the cerebello-pontine angle (CPA), 1 a transotic including the CPA and 1 a multilocular location. The tumors were removed surgically in 9 patients, whereas 3 patients opted for a "wait-and-test-and-scan" strategy. Of the surgical patients, 3 underwent labyrinthectomy and cochlear implant (CI) surgery in a single stage procedure; 1 patient received extended cochleostomy with CI surgery; 3 underwent partial or subtotal cochleoectomy, with partial cochlear reconstruction and CI surgery (n = 1) or implantation of electrode dummies for possible later CI following repeated MRI follow-up (n = 2); and in 2 patients, the tumors of the internal auditory canal and cerebellopontile angle exhibiting transmodiolar or transmacular growth were removed by combined translabyrinthine-transotic resection. For the intracochlear tumors, vestibular function could mostly be preserved after surgery. In all cases with CI surgery, hearing rehabilitation was successful, although speech discrimination was limited for the case with subtotal cochleoectomy. Surgical removal of intracochlear schwannomas via partial or subtotal cochleoectomy is, in principle, possible with preservation of vestibular function. In the authors' opinion, radiotherapy of ILS is only indicated in isolated cases. Provided performed early enough, cochlear implantation after surgical removal of ILS is an option for auditory rehabilitation, thus representing-in contrast to the "wait-and-test-and-scan" strategy-a therapeutic approach.