Neuropathology : official journal of the Japanese Society of Neuropathology
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Epithelioid glioblastoma (eGBM) is a rare variant of GBM which was adopted in the 2016 WHO classification. eGBM and pleomorphic xanthoastrocytoma (PXA) sometimes show overlapping features histologically and genetically, such as epithelioid pattern and a highly frequent V600E mutation in the gene for vRAF murine sarcoma viral oncogene homolog B1 (BRAF), respectively. Accurate diagnosis of these rare tumors is challenging according to the new criteria in the revised 2016 WHO classification. It is an urgent task to elucidate the biological properties of the tumors and to select appropriate treatment. ⋯ One PXA without BRAF mutation acquired TERT-p mutation at recurrence and one eGBM harbored both BRAF and TERT-p mutation. Molecular biological similarity between eGBM and PXA was suggested in our series, while degenerative changes reflected the features of PXA. It was speculated that the common genetic alterations for development and progression of eGBM and PXA might include BRAF and TERT-p mutations.