Presentation
Seizure
Patient Data
MRI through the temporal lobes of a patient with seizures demonstrates a high T2, low T1 region within the anterior mesial temporal lobe on the right. The central high T2 region does not attenuate on FLAIR.
Case Discussion
In cystic cortical tumours involving the temporal lobe, the general differential diagnosis includes:
The patient went on to have a resection.
Histology
Sections of the mesial structures show no evidence of mesial temporal sclerosis, or of significant dysplasia of the hippocampal formation. A dysembryoplastic neuroepithelial tumour is identified within white matter with focal extension within proximity of the dentate gyrus. The tumour is characterised by microcystic elements, scattered neurones, and oligodendroglial like cells that are occasionally organised in delicate cord-like structures. Features of cerebral microdysgenesis are evident in close proximity to the tumour, represented by small nodular aggregates of oligodendroglial like cells, and focal aggregates of neurones. Numerous corpora amylacea are observed within subpial regions, particularly in the vicinity of CA2.
FINAL DIAGNOSIS: Dysembryoplastic neuroepithelial tumour (DNET). No evidence of mesial temporal sclerosis.