Presentation
Not available.
Patient Data
MRI brain showing an enhancing left cerebellopontine angle tumor with extension into the left internal auditory promoting its enlargement. The mass seems to displace both the VII and VIII cranial nerves inferiorly. The remainder exam remains unremarkable.
MICROSCOPIC DESCRIPTION: Paraffin sections show fragments of a moderately hypercellular meningioma. This has a well developed syncytial architecture. The majority of tumor cells have uniform nuclear features. However, there are scattered foci in which tumor cells have rhabdoid features with eccentric nuclei and a large amount of granular eosinophilic cytoplasm. These features are seen in <50% of tumor cells. No anaplastic features in the form of mitoses or necrosis are seen. There is no evidence of brain invasion.
DIAGNOSIS: "Left cerebello-pontine angle tumor": Meningioma with focal rhabdoid features COMMENT: Foci of tumor cells with rhabdoid features indicate the potential for aggressive behavior. However, the criterion of at least 50% of tumor cells showing rhabdoid features, for a diagnosis of a WHO Grade III tumor, is not met.
Case Discussion
This cases illustrates a typical radiologic appearance of enhancing CPA mass, being the most likely differential diagnosis made between a schwannoma and a meningioma.
The histopathologic studied revealed a meningioma with the presence of foci of tumor cells with rhabdoid features indicating the potential for aggressive behavior. However, the criterion of at least 50% of tumor cells showing rhabdoid features, for a diagnosis of a WHO Grade III tumor, is not met.