Epidemiology of Supratentorial Dysembryoplastic Neuroepithelial Tumors in Children

Incidence and Prevalence

• Approximately 1% of brain tumors: The exact incidence of DNETs is not known. Since these tumors are often diagnosed in epilepsy surgery centers, a large selection bias is present in the data. In unselected series, DNETs make up approximately 1% of brain tumors, while in epilepsy centers they may account for 5–20 % of resective epilepsy surgeries.

Age Distribution

• Childhood and dependent on seizure onset: The age of patients in published series varies from infants (11, 16, 23, 25) to older adults (3, 5). The average age of seizure onset is in preadolescence (approximately 10 years of age). Most series have a large preponderance of cases in children. The diagnostic delay in early series was considerable, while in recent years diagnosis is made shortly after the onset of seizures.

Sex Predilection

• None: No clear sex predilection is found.

Geographic Distribution

• None: There is no known geographic predilection for DNET.

Risk Factors

• None: Currently, no risk factors have been identified for the development of DNET.

Relationships to Other Disease States, Syndromes

• Rare association with syndromic tumors: DNETs have not been associated with any known syndromes, apart from a single case report of an atypical DNET in a patient with nevus sebaceous syndrome. The significance of this anecdotal report is unclear. A few case reports of DNETs in NF1 patients also have been published. These authors (14) stress that molecular analysis did not show loss of the NF1 gene and that these DNETs may not be causally linked with neurofibromatosis.