Chromosome arm 1q gain is an adverse prognostic factor in localized and diffuse leptomeningeal glioneuronal tumors with BRAF gene fusion and 1p deletion
We previously described a series of localized intramedullary glioneuronal tumors limited to the spinal cord with histomorphologic, immunophenotypic, and molecular characteristics of diffuse leptomeningeal glioneuronal tumor (DLGNT), a newly added provisional entry in the current World Health Organization classification of central nervous system tumors [1, 3]. These localized spinal tumors and DLGNTs are characterized by the concomitant presence of KIAA1549–BRAF fusion and chromosome arm 1p deletion . Both have OLIG2-expressing oligodendrocyte-like tumor cells that are positive for synaptophysin and negative for GFAP . Neuropil-like islands surrounded by neurocytic cells and variable amounts of ganglion cell differentiation are additional distinct features of both diseases . However, despite this histomorphologic, immunophenotypic, and molecular resemblance, it remains uncertain whether the localized spinal BRAF-fused and 1p-deleted glioneuronal tumors are nosologically...
We thank Emily Walker in the Hartwell Center at St. Jude for technical assistance in genome-wide DNA methylation profiling and Vani Shanker in the Department of Scientific Editing at St. Jude for editing this manuscript.
JC receives funding from the American Lebanese Syrian Associated Charities (ALSAC) through St. Jude Children’s Research Hospital Department of Pathology.
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