Dysembryoplastic neuroepithelial tumor (DNT) in childhood
Nolan et al. examined the long-term outcome and prognostic featuresof DNT-associated epilepsy in 26 children managed surgically.Although 85% of children were seizure-free at 1 year, at longerfollow-up this fell to 62%. Residual tumor on postoperativeMRI was the most important factor in predicting long-term seizureoutcome.
Recurrence of DNT, gadolinium enhancedcoronal T1-weighted images. A. Postoperatively, there is residualenhancing DNT visible in medial right temporal lobe. B. Samepatient, 3 years later. DNT recurrence with increase in sizeof mass.
Dysembryoplastic neuroepithelial tumors (DNT) areglial-neuronal neoplasms that occur in children or young adults,typically in association with long-standing intractable partialseizures.1 They localize in cortex and inconsistently enhanceon MRI, and are characterized by columns of axon/oligodendroglialbundles that surround neurons floating in a pale, eosinophilicmatrix. Frequently they are associated with cortical dysplasias.DNTs are thought to be dysembryoplastic in origin and withoutpotential for recurrence once surgically removed.2
Nolan et al. extend our understanding of their natural historyby following 26 children with DNT for up to 11 years after initialdiagnosis and resection. They report an initial favorable prognosisfor seizure control, with 85% of children free of seizures 1year after diagnosis. Longer follow-up, however, demonstratesseizure recurrence in many other children. At the end of thestudy, only 65% remained free of seizures with mean follow-upof 4.3 years. Moreover, three of the children had tumor recurrence.This adds to a growing literature indicating that DNTs can recurafter resection, and may even undergo malignant transformation.3
Collectively, these results support a need for close follow-upof children and young adults who have been diagnosed and treatedfor DNT, monitoring for recurrence of seizures and for potentialof regrowth of the tumor.
References
Daumas-Duport C, Scheithauer BW, Chodkiewicz JP, et al. Dysembryo-plastic neuroepithelial tumor: a surgically curable tumor of young patients with intractable partial seizures. Report of thirty-nine cases. Neurosurgery. 1988; 23: 545556.[Medline]
Daumas-Duport C, Pietsch T, Lantos PL. Dysembryoplastic neuroepithelial tumors. In: Kleihues P, Cavinee WK, eds. WHO classification: tumours of the nervous system. Lyon: International Agency for Research on Cancer, 2000: 103106.
Hammond RR, Duggal N, Woulfe JMJ, Girvin JP. Malignant transformation of a dysembryoplastic neuroepithelial tumor. J Neurosurg. 2000; 92: 722725.[Medline]