LG-71MALIGNANT TRANSFORMATION OF A PEDIATRIC SPINAL CORD LOW-GRADE GLIONEURONAL TUMOR WITH BRAF DUPLICATION: A CASE REPORT

Abstract

LG-71. MALIGNANT TRANSFORMATION OF A PEDIATRIC SPINAL CORD LOW-GRADE GLIONEURONAL TUMOR WITH BRAF DUPLICATION: A CASE REPORT Ana Aguilar-Bonilla, Emily Owens Pickle, Rachel Gray, and Amy Smith; Arnold Palmer Hospital for Children, Orlando, FL, USA Pediatric low-grade glioma is the most common type brain tumor diagnosed in childhood. Low-grade tumors generally have a good prognosis and rarely undergo malignant transformation. We present the case of a patient with a low-grade glioneuronal tumor of the spinal cord with BRAF duplication that transformed into a high-grade poorly differentiated tumor 20 months after diagnosis. Recent studies have identified BRAF alterations in low-grade gliomas; two commonly described aberrations are KIAA1549-BRAF fusion and BRAFV600E mutation. BRAF fusion is more commonly seen in pilocytic astrocytomas and BRAF mutations in pleomorphic xanthoastrocytomas. Our patient was a 14 year old female with a spinal cord tumor that extended from C3-C4 to the conus medullaris. An aggressive sub-total resection was performed with residual tumor observed in the thoracic cord and conus medullaris. Pathology wasconsistentwith a low-grade tumor buthad local progression after an initial 3 month observation period. She received chemotherapy with Carboplatin and Vincristine. Fifteen months into treatment, imaging revealed disseminated leptomeningeal spread throughout the CNS. Repeat tumor biopsy was consistent with a high-grade tumor. Her tumor progressed rapidly despite chemotherapy and radiation. She developed abdominal seeding of her tumor and died of disease 22 months after initial diagnosis. Although it is still early to know the significance of these mutations, several studies have shown that BRAF fusion positive tumors have better outcome. Here we present an unusual case of a patient with BRAF fusion + low grade glioneuronal tumor with rapid progression into a highly malignant tumor with peritoneal dissemination. Neuro-Oncology 18:iii78–iii96, 2016. doi:10.1093/neuonc/now075.71 #The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.