Dysembryoplastic neuroepithelial tumor (DNET)

Case contributed by Dr David Mitchell

Presentation

Seizures.

Patient Data

Age: 40

16 x 15 mm cystic lesion in the posterior aspect of the right insula, which appears to be a cortically based tumor. The lesion is fluid signal on T2 weighted imaging, incompletely suppresses on FLAIR and does not show restricted diffusion. There is a surrounding rim of high T2 FLAIR signal. There is no associated contrast enhancement. MR perfusion shows no increase in rCBV. There is no susceptibility blooming in the lesion. The hippocampal formations are normal and symmetrical. No other intracranial lesion. No hydrocephalus.

Expected post-operative findings.

Case Discussion

Although this lesion does not have the classical "bubbly" appearance, it is a T2 hyperintense cortical based lesion in a patient with refractory epilepsy and DNET was favored based on the pre-operative imaging.

HISTOLOGICAL DIAGNOSIS: Brain, right frontal lesion: Features favoring dysembryoplastic neuroepithelial tumor (DNET), WHO Grade I.

MICROSCOPIC DESCRIPTION: Sections show a moderately cellular tumor composed of small round tumor cells set within a loose myxoid stroma. Tumor cells contain pale clear cytoplasm, round nuclei and inconspicuous nucleoli. Occasional floating neurons (NeuN positive) are identified. No mitoses, necrosis or microvascular proliferation are seen. Immunohistochemistry results show tumor cells stain: GFAP: Positive NogoA: Positive IDH1: Positive Topoisomerase proliferation index: 1%

PlayAdd to Share

Case information

rID: 62569
Published: 12th Sep 2018
Last edited: 13th Sep 2018
Inclusion in quiz mode: Included

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.