Abstract
Objective Most tumors of the internal auditory canal and cerebellopontine angle (CPA) are vestibular
schwannomas (VSs). Preoperative diagnosis is based on typical clinical symptoms and
radiological findings. In rare cases, histopathology can, however, show different
results.
Design This is a retrospective chart and database review.
Setting The study was conducted at a tertiary skull base referral center at a university
hospital.
Participants A total of 207 consecutive cases of VS surgery via the middle cranial fossa approach
performed between December 2005 and January 2015 were reviewed.
Main Outcome Measures The main outcome measures were definitive histologic findings in 198 specimens, analysis
of preoperative magnetic resonance imaging (MRI) and computed tomography.
Results Histopathology revealed three meningiomas and two cases of lipochoristomas. Clinical
presentation was typical for VS in all five cases. In preoperative MRI, all tumors
were suspected to be VSs. Retrospective analysis of the preoperative imaging did not
lead to a modification of the diagnosis. Intraoperative findings showed increased
adherence of the tumor to the adjacent tissue in two of the five cases.
Conclusion CPA lesions other than VSs are unusual but have to be taken into account. In very
small tumors, imaging still remains difficult.
Keywords
histology - vestibular schwannoma - imaging - small tumor - middle cranial fossa approach
