Presentation
Headache, vertigo, and parietal scalp swelling.
Patient Data
MRI and MRV of the brain demonstrate a large intensely enhanced multilobulated extra-axial mass with central areas of cystic changes at the high parietal parasagittal region with direct extension through the skull and into the scalp soft tissues.
Extension of the mass toward the underlying brain caused subfalcine herniation and significant mass effect upon the corpus callosum body.
Invasion of the mass to the superior sagittal sinus with displacement is seen as well.
Case Discussion
Microscopic diagnosis:
Solitary fibrous tumor (previously known as hemangiopericytoma) with foci of high mitotic activity and necrosis compatible with anaplastic transformation. WHO grade III.
Bone invasion is noted.
IHC result:
- EMA: Negative
- CD34: Positive in endothelial cells
- CD 99: Weakly positive
- Ki-67: Positive in up to 4% of tumor cells
Findings are consistent with hemangiopericytoma with focal anaplastic transformation, WHO grade III.
Note: at the time of diagnosis/case contribution this tumor was known as a hemangiopericytoma. Under the 5th Edition (2021) of the WHO classification of CNS tumors, it is now considered a solitary fibrous tumor of the dura.