Fig. 1
Three radiologically and histologically different neoplasms in F48 IDH-mutant glioblastoma with FGFR2 alterations. a Timeline of disease progression. b Initial axial MRI shows a rim-enhancing, T2W hyperintense and T2W-FLAIR hypointense mass (blue arrow), Sylvian fissure enhancement (red arrow), and extensive white matter infiltration (green arrow), each corresponding to a different tumor. c H&E and IHC with indicated antibodies of the resected rim-enhancing mass (Res1). Note HG neuroendocrine/embryonal morphology with hyperchromatic nuclei and frequent mitoses (arrow). IHC with Cam5.2, TTF-1, HMB-45, p40, p63, CD45, estrogen receptor and mammaglobin to exclude a metastatic neoplasm showed negative results (not shown). d Autopsy showing the entire brain base covered in a thick, nodular, hyperemic or hemorrhagic LM infiltrate. e Gross and microscopic appearance of the HG LM infiltrate. Sections S3 and S4 show the resection site (blue arrows) and the Sylvian fissure LM neoplasm (red arrow). H&E and IHC with indicated antibodies of the Sylvian fissure LM tumor (LMS4). f H&E and IDH-R132H reactivity of the LG DI neoplasm from S6 white matter (DIS6). g Close-up H&E of the HG LM component showing rhabdoid cells embedded in myxoid ECM. h Ultrastructural evaluation showing true rhabdoid cells with perinuclear whorls of intermediate filaments, and numerous mitotic figures. IHC for vimentin shows strong positivity in the whorls