ABSTRACT
In a series of 179 cerebellopontine angle (CPA) tumors, the authors present nine cases
(5%) that were cochlear nerve neuromas. There were six men and three women (mean age,
51 years). Preoperative magnetic resonance imaging confirmed the diagnosis in one
case with a labyrinthine extension and raised suspicions in the other four cases,
which were confirmed during surgery. The remaining neuromas were discovered intraoperatively.
The mean time between first observation and surgery was 9 months. Preoperatively,
all patients underwent a complete otoneurological assessment. The middle fossa approach
was used for the patient with the labyrinthine extension, and the retrosigmoid approach
was used for the other eight cases. In all patients facial nerve function was preserved.
Sudden or major hearing loss without associated vestibular symptoms or preoperative
facial paralysis may be predictive of a cochlear component of a CPA tumor. The near-field
relationships of cochlear neuromas located at the level of the acoustic and facial
nerves can be appreciated because of their small size and strong contrast enhancement.
KEYWORD
Cochlear neuroma - cochlear schwannoma
