In cystic cortical tumours involving the temporal lobe, the general differential diagnosis includes:
The patient went on to have a resection.
Microscopic Description: Sections of the mesial structures show no evidence of mesial emporal sclerosis, or of significant dysplasia of the hippocampal formation. A dysembryoplastic neuroepithelial tumor is identified within white matter with focal extension within proximity of the dentate gyrus. The tumor is characterized by microcystic elements, scattered neurons, and oligodendroglial like cells that are occasionally organized in delicate cord-like structures. Features of cerebral microdysgenesis are evident in close proximity to the tumor, represented by small nodular aggregates of oligodendroglial like cells, and focal aggregates of neurons. Numerous corpora amylacea are observed within subpial regions, particularly in the vicinity of CA2.
Final Diagnosis: Dysembryoplastic neuroepithelial tumor (DNET). No evidence of mesial temporal sclerosis.