One patient with a periventricular low-grade glioneuronal neoplasm (DNET-like) later developed a new, non-continuous right temporal lobe mass, which was subsequently resected (13 months after diagnostic surgery and following treatment with craniospinal irradiation); both primary and recurrent metastatic specimens were found to have the same aforementioned mutations in CDH1 (A298T) and FGFR1 (K656_T658 > MTP) on sequencing and were otherwise negative for BRAF, FGFR1, NTRK2, MYB, or MYBL1 rearrangements, CDKN2A deletions, or BRAFV600E or IDH1 mutations (Patient #45, Fig. 1). This evidence concerns the gene IDH1 and dysembryoplastic neuroepithelial tumor.