Pediatric Intracochlear Schwannoma: Case Series and Review of the Literature

Abstract

Background: Intracochlear schwannomas (ICSs) are a subtype of intralabyrinthine schwannomas, completely located in the cochlear lumen. ICSs are particularly rare in the pediatric population. Putative diagnosis is made on the basis of magnetic resonance findings with signal characteristics that should remain the same at follow-up imaging.

Methods: A retrospective review was performed searching for pediatric patients affected by ICS treated at the Otolaryngology Department, Ospedale Ramazzini, Carpi (Italy), and Otolaryngology and Otoneurosurgery Department, Azienda Ospedaliero-Universitaria di Parma, (Italy). A scoping literature review of the period January 2000 - June 2024 was performed.

Results: Two cases of ICS in pediatric patients are described. Neither family history nor genetic signs of neurofibromatosis type II were found. A single report was identified in the literature review. Data analysis resumes the pooled data of the latter case and the authors' patients. The most common symptom at presentation was progressive sensorineural hearing loss (66%). Mean pure tone average at diagnosis was 74.2 dB. Intracochlear location was in the basal turn in 2 cases and in the apical and middle turns in the third patient. All cases initially underwent a "wait and scan" strategy. The mean follow-up time was 23.3 months.

Conclusion: Management planning of pediatric ICSs should be accurate as surgical removal may require partial or total cochlear demolition, resulting in vestibular dysfunction and precluding future positioning of a cochlear implant. Close clinical and radiological follow-up with serial MRI scans allows to evaluate both symptom progression and rate of growth, in order to provide patients with the best therapeutic option.

Keywords: Intracochlear schwannoma; intralabyrinthine schwannoma; pediatric schwannoma; sensorineural hearing loss.

Figure 1.

Patient 1, Axial MRI images of the right inner ear and internal acoustic meatus. T2 sequences show a signal void in the basal perimodiolar cochlear region.

Figure 2.

(a-b) Patient 2, Axial MRI images of the left inner ear and internal acoustic meatus. T2 sequences show a signal void in the middle/apical cochlear region (a). T1 sequences after gadolinium administration show an area of signal hyperintensity (arrowhead) in the middle/apical cochlear region (b).