Dysembryoplastic neuroepithelial tumor (DNET) associated with dysgenesis of the corpus callosum

The axial contrast-enhanced CT study shows a relatively well-demarcated cortically-based hypoattenuated lesion seen involving the lower posterior right frontal lobe, including the right inferior subcentral gyrus, without significant enhancement, mass effect, or calcification. The study also shows features suggestive of corpus callosum agenesis.

The MRI study shows a well-demarcated cortically-based lesion that appears with a hyperintense signal on T2WI, with a bubbly appearance, and hypointense in T1WI without significant enhancement or mass effect. A thin, hyperintense rimis seen in the FLAIR study. Subtle scalloping of the overlying cranial bone is seen, denoting chronicity. Features of partial agenesis of the corpus callosum (CC) are also noted, manifested by the absence of the body and splenium of the CC, with relative preservation of the genu and rostrum. The lateral ventricles show a typical "racing car" appearance on the axial plane.

Dysembryoplastic neuroepithelial tumour (DNET) is a unique type of low-grade glioneuronal tumour, usually presentedpresenting with childhood and adolescenceor adolescent epilepsy refractory to medical treatment. DNETs are slow-growing tumours arising from the cerebral cortex, usually involving a wholean entire gyrus or a wedge-shaped part of a cerebral lobe. Pathologically, typical DNETs comprise the tumour core surrounded by the rim of dysplastic cortex; this rim of dysplastic cortex is regarded as highly epileptogenic. Complete resection of the tumour is crucial for seizure control. This tumourDNET appears on CT as a low-attenuating cortically based mass with extension ininto the subcortical area. MRI is the imaging modality of choice for diagnosing DNET. It usually demonstrates a bubbly appearance with low signal intensity inon T1W images and high signal on T2W images and FLAIR, without noticeable enhancement. Poor enhancement is a usualcommon feature to distinguishthat distinguishes DNET from gangliogliomas, which commonly demonstrateusually show intense enhancement. The differential diagnosis in this particular case is between DNET and a low-grade glioma. The imaging characteristics and presentation of the patient align more favourably with the former.

Dysgenesis of the corpus callosum represents an in utero developmental anomaly characterised by incomplete development of the corpus callosum. ManyIt is associated with many other CNS associations are notedanomalies, including Chiari II malformation, Dandy-Walker Spectrumspectrum, grayand grey matter heterotopia, andamong others. However, there is still no clearclearly proven association between this anomaly and DNETs is provedDNET.