The pathological diagnosis was: Gemistocytic astrocytoma (WHO grade II)

Comment: Although the features are in keeping with a grade II tumor, a significant proportion of gemistocytes (as in this case) tends to progress more rapidly than ordinary fibrillary astrocytoma.

Gemistocytic astrocytoma is a histologic subtype of low-grade astrocytoma, with a poorer prognosis than other matched WHO grade tumors, and with no specific imaging features, however, they are typically presented with features that suggest higher grade tumors. 

Note: IDH mutation status is not provided in this case and according to the current (2016) WHO classification of CNS tumors, this tumor would, therefore, be designated as a diffuse astrocytoma NOS.