DNET (dysembryoplastic neuroepithelial tumor)
Findings:
A small mass is present in the right temporal lobe which
has a few foci of calcification on CT, a variable intensity rim on MR,
a T1 hypo/T2 hyper center, no enhancement, and minimal associated surrounding
signal abnormality.
Differential Diagnosis:
DNET, low grade astrocytoma, oligodendroglioma, ganglioglioma,
hamartoma (TS), metastasis less likely
Discussion:
DNET is a slow growing, benign mixed neuronal/glial tumor
with a predilection for the temporal lobes. Clinically, patients present
with chronic intractable partial complex seizures. Imaging is nonspecific
CT hypodense/T1 hypo/T2 hyper. Calcification, edema, mass effect, and enhancement
are uncommon. A cyst/mural nodule may be seen but is rare. Occasionally,
the tumor may present as a megagyrus with normal white matter coursing
into the lesion.