Presentation
Hearing loss for investigation.
Patient Data
Enhancing masses completely occupy the internal acoustic canals bilaterally, with extension into the cerebellopontine angles but without mass effect on the brainstem.
The patient was monitored with serial MRIs for a number of years, with gradual enlargement of the masses. Eventually the patient became symptomatic from brainstem compression, and underwent debulking.
Histology
MICROSCOPIC DESCRIPTION: The sections show a moderately cellular schwannoma. It mainly contains Antoni A areas with fascicles of spindle cells. There is focal palisading with Verocay body formation. A small amount of Antoni B areas with microcystic change is also seen. The tumor cells show focal ancient change with moderate nuclear enlargement and smudged chromatin pattern. Mitoses are inconspicuous. No evidence of malignancy is identified.
DIAGNOSIS: Brain tumor: Schwannoma.
Case Discussion
Bilateral vestibular schwannomas are considered pathognomonic for neurofibromatosis type 2, with other manifestations of this disease including meningiomas and ependymomas.