The patient went on to have a resection. 

Histology

 A low-grade glioneuronal tumor is located in the cortex and white matter and contains cystic elements. Floating neurons are observed. Neurocytic-type cells are also noted. In addition to the dysembryoplastic neuroepithelial tumor, varying degrees of cerebral microdysgenesis are also observed, represented by small aggregates of neurons and neurocytic type cells, and increased numbers of ganglion type cells within white matter. Mesial temporal sclerosis is not defined.

Final diagnosis: dysembryoplastic neuroepithelial tumor (DNET).