Rare-36. Dysembryoplastic Neuroepithelial Tumors: A Review of Clinical and Molecular Characteristics, and Outcome in a Pediatric Population at a Single Center

Abstract

BACKGROUND Neuronal and mixed neuro-glial tumors of the central nervous system (CNS) are relatively rare. Dysembryoplastic neuroepithelial tumor (DNET) is a benign, rare, slow-growing tumor, but in many cases is associated with intractable epilepsy. OBJECTIVE To report the experience with DNET at a single free-standing children’s institution. METHODS A retrospective chart review of 24 patients with confirmed DNET between 2001 and 2019 was performed. Data was collected on clinical characteristics, tumor location, surgical management, histopathological and molecular findings, and outcomes. RESULTS Mean age at diagnosis was 10 years (range 2 to 19 years), with female predominance (54.2%). Most common presenting symptoms were seizures (79.2%) and headaches (12.5%). Location of the tumor was temporal (29.2%), frontal (25.0%), parietal (16.7%), cerebellar (12.5%) and occipital (4.2%). A gross total resection was achieved in half the cases. Recurrence occurred in 4 patients (16.7%), all of whom had subtotal resections. The average follow up since diagnosis was 4.6 years (range 0.3 to 14 years). Nineteen patients presented with seizures, of which 63.2% were seizure free after surgery. The samples with molecular genetic testing (microarrays or FISH), were all normal except one patient positive for BRAF V600E mutation. CONCLUSIONS This is the first and largest review of pediatric DNETs in the last 10 years. Despite majority of patients having a favorable outcome after surgery, a subset of patients remains symptomatic. As molecular mechanisms in DNET remain unknown, future aim is to describe the molecular characteristics of our DNET population, and correlate with outcomes.