BRAF V600E Mutations are Frequent in Dysembryoplastic Neuroepithelial Tumors and Subependymal Giant Cell Astrocytomas

BackgroundBRAF mutation has received a great deal of attention in neuro-oncology field, recently. This study aimed to investigate the incidence and the clinical significance of BRAF(V600E) in low-grade glial tumors. MethodsAn institutional cohort of 105 brain tumors (51 dysembryoplastic neuroepithelial tumors (DNTs), 14 subependymal giant cell astrocytomas (SEGAs), 12 glioblastoma with neuronal marker expression (GBM-N), and 28 pleomorphic xanthoastrocytomas (PXAs)) from 100 patients were investigated for the presence of BRAF(V600E) by direct sequencing. ResultsWe found frequent BRAF(V600E) in DNTs (26/51, 51%), SEGAs (6/14, 42.9%), and PXAs (14/28, 50%). In DNTs, BRAF(V600E) was more commonly detected in tumors with extra-temporal location (68.2% vs. 37.9%; P=0.032). The diagnostic subgroups of tuberous sclerosis complex were not correlated with BRAF(V600E) in patients with SEGA (P=0.533). One PXA case revealed a unique duplication mutation (p.Thr599dup) of codon 599. All GMB-N cases did not carry BRAF mutation. ConclusionsOur data indicate that BRAF(V600E) is a common genetic alteration in low-grade glial tumors with neuronal component or differentiation. High frequency of BRAF(V600E) in DNTs and SEGAs would be useful in the differential diagnosis, and also offers a potential specific treatment targeting BRAF(V600E). J. Surg. Oncol. 2015 111:359-364. (c) 2014 Wiley Periodicals, Inc.