Hemangiopericytoma - foramen magnum


MRI features of an enhancing extra-axial mass of the foramen magnum, extending to the hypoglossal canal, compressing and displacing the medulla oblongata (schwannoma vs meningioma).

The patient underwent left occipital craniotomy with partial resection of the tumor.  The histopathological exam confirmed the diagnosis of hemangiopericytoma.

Extramedullary tumors of the foramen magnum are relatively rare. The most common are nerve sheath tumors and meningiomas, hemangiopericytoma is very rare in this location.