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Figure legends :
Figure 1. A,B,C: Demographic profile of the cohort; D: Kaplan Meier curve depicting the overall survival in patients with ETANTR versus EBL versus others.
Figure 1S (case #12). A: T1 Sagittal MRI plane showing well demarcated iso to hypo intense lesion in pons; B: T2 axial MR showing well defined hyper intense lesion on right side of pons mimicking an extra axial lesion; C: FLAIR images show ill-defined margins suggesting an intra axial lesion with possible exophytic component; D: Post contrast axial MR showing non enhancing lesion expanding the pons on right side; E: Post contrast sagittal MRI showing non enhancing lesion; F:3D turbo spin T2 image defining the lesion; G: Diffusion weighted MR suggesting a cellular tumor; F:T1 coronal MR showing the extent of lesion.
Figure 2: Embryonal tumor with abundant neuropil and true rosettes. A: Biphasic histological pattern with cellular islands within abundant neuropil (H&E, scale bar, 100µm); B: Multilayered rosettes present within sheets of embryonal cells (scale bar, 50µm); C: Cellular islands with embryonal cells disposed in sheets, several mitotic figures and apoptotic debris is noted in the background (scale bar, 20µm); D: Multilayered rosettes with a central lumen surrounded by mitotically active cells (scale bar, 20µm).
Figure 3. Embryonal tumor with abundant neuropil and true rosettes. A: High magnification depicting the characteristic multilayered rosettes with central lumina showing secretions (scale bar, 10µm); B: Nodular clusters of embryonal cells present within abundant neuropil (scale bar, 50µm);C: Corresponding section showing diffuse strong immunoreactivity for LIN 28A within the embryonal cells (scale bar, 50µm); D: Diffuse strong nuclear expression for INI-1 protein (scale bar 50µm); E,F: Focal positivity for synaptophysin (E) and GFAP (F) within the embryonal cells (scale bar, 50µm); ; G: Scant positivity for Vimentin within the embryonal cells (scale bar, 20µm); H: Ki67 revels a high proliferative index (scale bar, 50µm); I: Ki67 highlights the multilayered rosettes composed of mitotically active cells around the central lumen (scale bar, 50µm).
Figure 4 . Ependymoblastoma pattern . A: Sheets of embryonal cells with numerous multilayered and perivascular rosettes with scant neuropil stroma in the background (scale bar, 50µm); B: High magnification depicting closely packed multilayered rosettes (scale bar, 20µm); C: Poorly formed multilayered rosettes (scale bar, 20µm); D: Strong and diffuse immunoreactivity for LIN 28A within the embryonal cells (scale bar, 50µm); E: Retained widespread nuclear expression for INI-1 protein (scale bar, 50µm).
Figure 5: Medulloepithelioma pattern. A: Embryonal cells disposed in papillary arrangements of neoplastic pseudostratified neuroepithelium (scale bar, 50µm); B: Sheets of embryonal cells in zones away from tubular and papillary structures (scale bar, 50µm); C, D: High magnification depicting pseudostratified neuroepithelium around the vascular cores (scale bar, 20µm); E: Strong and diffuse immunoreactivity for LIN 28A within the embryonal cells (scale bar, 20µm); F: Focal, weak immunoreactivity for cytokeratin (scale bar, 20µm); G: GFAP was not expressed by the tumor cells (scale bar, 20µm); H: Retained widespread nuclear expression for INI-1 protein (scale bar, 10µm).