An extra-axial mass in the right cerebellopontine angle with a prominent central cyst.
MRI through the posterior fossa demonstrates an extra-axial mass in the right cerebellopontine angle with a prominent central cyst. It does not enter the internal acoustic meatus and does result in edema in the adjacent cerebellar hemisphere.
Features are consistent with a cystic meningioma. As the mass seems to be separate from the eighth cranial nerve, a schwannoma is thought much less likely.
Case Discussion
This patient went on to have a resection.
Histology
Sections show a cellular tumor with the histologic features of meningioma. The tumor cells show uniform nuclei without mitotic activity and are arranged in interlacing bundles with occasional formation of whorls. Rare psammoma bodies are identified.
FINAL DIAGNOSIS: meningioma