Preservation of function is an important goal during surgical management of cochleovestibular schwannomas. We here demonstrate the relief of vertigo and the preservation of function of all five vestibular receptors after removal of an intracochlear schwannoma with extension to the fundus of the internal auditory canal. A 61-year-old male with a five-year history of left-sided deafness, tinnitus, vertigo attacks, and an MRI consistent with an intracochlear schwannoma with limited extension through the modiolus to the fundus of the internal auditory canal (IAC) underwent transcanal, transcochlear total tumor removal and-due to a cerebrospinal fluid leak from the fundus of the IAC-revision surgery with lateral petrosectomy and blind sac closure of the external auditory canal. Despite complete removal of the cochlear partition of the inner ear (total cochlectomy), the patient\'s vestibular receptors remained functional, and the vertigo symptoms disappeared. These results show that vestibular labyrinthine function may not only be preserved after partial or subtotal cochlectomy but also after complete cochlear removal. This further confirms the vestibular labyrinth\'s robustness and encourages surgical management of transmodiolar schwannomas with limited extension to the fundus of the IAC.

OBJECTIVE: The aim was to analyze the long-term hearing results after simultaneous microsurgical extirpation via enlarged cochleostomy and cochlear implantation in intracochlear schwannoma as compared with non-tumor single-side deafness patients.
METHODS: Microsurgical extirpation via enlarged cochleostomy with simultaneous cochlear implantation was performed in 15 cases of intracochlear schwannoma between 2014 and 2021. Speech recognition tests in German language and impedance performances were collected over 36 months of observation and compared with an internal cohort of 52 age matched non-tumor single-side deafness patients. Retrospective cohort study in a tertiary referral center.
RESULTS: The surgery proved feasible and uneventful in all cases. In the case of intracochlear schwannoma, the hearing rehabilitation results were highly satisfactory and comparable to those of the non-tumor single-side deafness cohort. The speech recognition performance improved steadily in the first 12 months; afterward, it remained stable, providing indirect evidence against tumor recurrence during the follow-up. One patient required implant revision surgery related to device failure, but no recurrence was registered in the 36 months of observation.
CONCLUSIONS: Cochlear implantation is the strategy of choice for hearing rehabilitation in case of intracochlear schwannomas in the long term. In particular, the combination of tumor extirpation via cochleostomy with a cochlear implantation in the same surgical time offers a viable therapy for intracochlear schwannoma, granting a sufficient degree of radicality without compromising the cochlear integrity. This technique allows for revision surgery if required.
METHODS: 4 Laryngoscope, 134:1854-1860, 2024.

Intralabyrinthine schwannomas (ILS) are rare benign tumors, often responsible for hearing loss. MRI is important in establishing the diagnosis. We present the example of a 48-year-old lady who reported a 3-years history of right-sided sensorineural deafness. MRI demonstrated a loss of the normal hypersignal of the second turn of the right cochlea compatible with intracochlear schwannoma.

Intracochlear schwannoma is very rare, and complete loss of hearing is inevitable after the removal of this tumor. Here, we discuss cochlear implantation (CI) performed simultaneously with the removal of an intracochlear schwannoma.
Retrospective single-center study.
Tertiary medical institute.
Simultaneous CI and intracochlear schwannoma removal were performed in 4 subjects. After subtotal cochleostomy, the tumors were removed meticulously, with preservation of the modiolus. A new slim modiolar electrode (Nucleus CI632) was placed in a manner that hugged the modiolus. The surgical outcomes of functional gain, word recognition score (WRS), sound localization, and hearing in noise and speech intelligibility tests were investigated.
Intracochlear schwannomas were removed successfully from the 4 patients, with no remnant tumor. The mean aided hearing threshold 6 months after surgery was 25.0 ± 1.8 dB, and the mean-aided WRS with a 60 dB stimulus was 36.0 ± 18.8% (range 16%-60%). The Categorical Auditory Performance (CAP) score of the 3 single-sided deafness patients under contralateral ear masking was 7. The CAP score of the patient with bilateral sensorineural hearing loss was 6, which improved from a preoperative score of 0.
When an intracochlear schwannoma does not completely invade the modiolus, CI with simultaneous tumor removal can be performed successfully, resulting in good hearing performance. A slim modiolar electrode can be placed stably at the modiolus after schwannoma removal.

Intra-labyrinthine schwannomas are rare. We present a case of a 50-year-old male with non-serviceable unilateral sensorineural hearing loss and tinnitus. CE-MRI revealed an enhancing signal in the basal turn of left cochlea suggestive of a schwannoma. A trans-mastoid standard facial recess approach was used for tumor excision. At one year follow up, patient is disease free.

A primary intracochlear schwannoma (ICS) is a unique type of vestibular schwannoma (VS); the tumor originates from the terminal branches of the cochlear nerve and is confined to the cochlea. An ICS is the most common subtype of schwannoma in the inner ear. As an ICS is clinically rare, diagnosis and treatment remain challenging. We report a rare case of cochlear implantation (CI) in a patient with neurofibromatosis type 2 and an ICS. The patient exhibited bilateral, profound, sensorineural hearing loss. The tumor on one side was a common VS treated via tumor and acoustic nerve resection and that on the other side an ICS. To ensure auditory rehabilitation via CI, we performed CI while removing part of the ICS via an enlarged round window. Auditory rehabilitation was satisfactory. Thus, ICS patients, especially those who urgently require auditory rehabilitation, can undergo simultaneous CI and (total or partial) tumor removal. However, the long-term results require close observation.

Schwannomas of the eighth cranial nerve are benign tumours commonly found in the internal auditory meatus or in the cerebellopontine angle. In most cases, they arise from the inferior or vestibular portion of the vestibular nerve. Rarely, these tumours present in the inner ear and are then called intralabyrinthine schwannomas. Bilateral schwannomas are known in neurofibromatosis type 2 (NF2). Bilateral and ipsilateral, multilocular sporadic schwannomas of the eighth cranial nerve have been described as extremely rare findings. This report describes the first case of bilateral sporadic intracochlear schwannomas in a patient with no genetic or clinical features of NF2.
UNASSIGNED: Schwannome des achten Hirnnerven sind gutartige Tumoren und präsentieren sich in der Regel im inneren Gehörgang oder/und im Kleinhirnbrückenwinkel. Am häufigsten gehen sie hier von vom N. vestibularis inferior oder superior aus. Selten sind die Tumoren auch im Innenohr lokalisiert; sie werden dann als intralabyrinthäre Schwannome bezeichnet. Bilaterale Tumoren treten bei Neurofibromatose Typ 2 (NF2) auf. Bilaterale und ipsilaterale, multilokuläre, sporadische Vestibularis‑/Cochlearis-Schwannome wurden als extrem seltenes Vorkommen bereits beschrieben. Der vorliegende Bericht beschreibt den ersten Fall beidseitiger intracochleärer Schwannome in einer Patientin ohne genetische oder klinische Zeichen einer NF2.

Schwannomas of the eighth cranial nerve are benign tumours commonly found in the internal auditory meatus or in the cerebellopontine angle. In most cases, they arise from the inferior or vestibular portion of the vestibular nerve. Rarely, these tumours present in the inner ear and are then called intralabyrinthine schwannomas. Bilateral schwannomas are known in neurofibromatosis type 2 (NF2). Bilateral and ipsilateral, multilocular sporadic schwannomas of the eighth cranial nerve have been described as extremely rare findings. This report describes the first case of bilateral sporadic intracochlear schwannomas in a patient with no genetic or clinical features of NF2.

Intralabyrinthine schwannomas (ILS) are rare tumors that frequently cause sensorineural hearing loss. The development and increased use of magnetic resonance imaging in recent years have facilitated the diagnosis of these tumors that present with otherwise nondiscriminant symptoms such as tinnitus, vertigo, and hearing loss. The following is a review of the presentation, pathophysiology, imaging, and treatment with a focused discussion on auditory rehabilitation options of ILS.

Intracochlear schwannomas can occur either as an extension of a larger tumor from the internal auditory canal, or as a solitary labyrinthine tumor. They are currently removed via a translabyrinthine approach extended to the basal turn, adding a transotic approach for tumors lying beyond the basal turn. Facial bridge cochleostomy may be associated with the translabyrinthine approach to enable the whole cochlea to be approached without sacrificing the external auditory canal and tympanum. We describe seven cases, five of which underwent cochlear schwannoma resection with facial bridge cochleostomy, one case with the same procedure for a suspect tumor and one, previously subjected to radical tympanomastoidectomy, who underwent schwannoma resection via a transotic approach. Facial bridge cochleostomy involved removing the bone between the labyrinthine and tympanic portions of the fallopian canal, and exposing the cochlea from the basal to the apical turn. Patients\' recovery was uneventful, and long-term magnetic resonance imaging showed no residual tumor. Facial bridge cochleostomy can be a flexible extension of the translabyrinthine approach for tumors extending from the internal auditory canal to the cochlea. The transcanal approach is suitable for the primary exclusive intralabyrinthine tumor. The indications for the different approaches are discussed.