The patient went on to have surgery and oligodendroglioma histology identified.

Note: This tumor predates the recent (2016) revision WHO classification of CNS tumors, and thus molecular markers (IDH mutation and 1p19q co-deletion) are not available. As such, this tumor would now be classified as oligodendroglioma NOS.

Note: Historically, oligodendrogliomas were considered well-circumscribed tumors, however when defined on the basis of IDH-mutation and 1p19q co-deletion, oligodendrogliomas appear to be a group of tumors with different morphology and recent studies suggest that in fact they have poorly defined borders ¹. As such, it is at least possible that this case represents a diffuse astrocytoma according to current classification.