Abstract
Introduction Schwannomas of the eighth cranial nerve are benign tumors that usually occur in the
internal auditory canal or the cerebellopontine angle cistern. Rarely, these tumors
may originate from the neural elements within the vestibule, cochlea, or semicircular
canals and are called intralabyrinthine schwannomas. Intracochlear schwannomas (ICSs) represent a small percentage of these tumors, and
their diagnosis is based on high-resolution magnetic resonance imaging (MRI).
Objectives To report the clinical and radiologic features and audiometric testing results of
an ICS in a 48-year-old man after a 22-month follow-up period.
Resumed Report A patient with an 8-year history of persistent tinnitus in his right ear, combined
with ipsilateral progressive hearing loss and aural fullness. Audiometry revealed
normal hearing in the left ear and a moderate to severe sensorineural hearing loss
in the right ear, with decreased speech reception threshold and word recognition score,
compared with the exam performed 5 years previously. MRI showed a small intracochlear
nodular lesion in the modiolus, isointense on T1 with a high contrast enhancement
on T1 postgadolinium images. During the follow-up period, there were no radiologic
changes on imaging studies. Thus, a wait-and-scan policy was chosen as the lesion
remained stable with no considerable growth and the patient still presents with residual
hearing.
Conclusions Once diagnosed, not all ICS patients require surgery. Treatment options for ICS include
stereotactic radiotherapy and rescanning policy, depending on the tumor's size, evidence
of the tumor's growth, degree of hearing loss, intractable vestibular symptoms, concern
about the pathologic diagnosis, and the patient's other medical conditions.
Keywords
intracochlear schwannoma - sensorineural hearing loss - acoustic neuroma - temporal
bone tumor - transotic approach - magnetic resonance imaging
