case_images: PMC6488779_01
case_images: A, Sagittal short-Tau inversion recovery image through the cervical and upper thoracic
  spine shows diffuse cord infiltration and expansion by a hyperintense mass with focal
  increased heterogeneity in the lower cervical cord (arrow). B, Sagittal short-Tau
  inversion recovery image through the lower thoracic spine shows inferior extent of the
  hyperintense spinal cord mass to the T8 level (arrow). The expansile cord mass nearly
  fills the thecal sac. C, Sagittal T1 postcontrast image shows subtle peripheral
  enhancement in the lower cervical cord surrounding an area of nonenhancement likely
  representing necrosis (arrow). D, Sagittal T1 postcontrast image shows subtle
  leptomeningeal enhancement (double arrows).
case_images: 10.1177_2329048X19842451-fig1.jpg
case_images: PMC6488779_01_10.1177_2329048X19842451-fig1.jpg
case_images: fig1-2329048X19842451
case_images: Magnetic resonance imaging (MRI) of the neuroaxis showed an abnormal appearance of the cervical and thoracic spinal cord with expansion and irregular areas of enhancement (Figure 1).
case_images: A and B, Sagittal fluid-attenuated inversion recovery and postcontrast T1W images do
  not show intracranial lesion on the initial scan. C, Sagittal fluid-attenuated inversion
  recovery through brain midline shows extensive metastasis along the brain stem,
  cerebellum, and tuber cinereum (arrow). D, Sagittal postcontrast T1W through brain
  midline shows faint, scattered enhancement in the extensive metastasis along the brain
  stem, cerebellum, and tuber cinereum (arrow).
case_images: 10.1177_2329048X19842451-fig2.jpg
case_images: PMC6488779_01_10.1177_2329048X19842451-fig2.jpg
case_images: fig2-2329048X19842451
case_images: Initial MRI brain was unremarkable (Figure 2A and B). The patient also required a tracheostomy to maintain the airway but died within 4 months after diagnosis as a result of intracranial spread of this metastatic disease (Figure 2C and D).
case_images: Microscopic examination demonstrates a moderately cellular glial neoplasm with a
  nodular growth pattern (A, x10); the tumor cells have irregular, hyperchromatic nuclei,
  and scant cytoplasm (B, x40); occasional mitotic figures are identified (C, x40); the
  Ki-67 proliferation index is estimated at up to 12% (D, x10); glial fibrillary acidic
  protein (GFAP) immunoreactive is shown in tumor cells (E, x40); an immunostain for
  H3K27M mutant protein shows strong nuclear positivity.
case_images: 10.1177_2329048X19842451-fig3.jpg
case_images: PMC6488779_01_10.1177_2329048X19842451-fig3.jpg
case_images: fig3-2329048X19842451
case_images: After several weeks, the pathology specimen examination revealed the diagnosis of diffuse midline glioma (World Health Organization [WHO] grade IV; Figure 3).
case_images: Posttreatment sagittal short-Tau inversion recovery through the cervical cord shows
  significant improvement in cord expansion and signal, although some heterogeneity at C6
  to C7 remains (arrow). Posttreatment sagittal short-Tau inversion recovery through the
  thoracic cord shows improvement in cord expansion. Signal heterogeneity and areas of
  myelomalacia are seen (arrow). Posttreatment sagittal postcontrast T1W image through
  cervical cord shows linear diffuse leptomeningeal enhancement (arrow). Posttreatment
  sagittal postcontrast T1W image through thoracic cord shows intraparenchymal patchy
  enhancement in the mid thoracic cord (arrow). Thick, leptomeningeal enhancement (sugar
  coating) along the conus medullaris surface (double arrows).
case_images: 10.1177_2329048X19842451-fig4.jpg
case_images: PMC6488779_01_10.1177_2329048X19842451-fig4.jpg
case_images: fig4-2329048X19842451
case_images: Subsequently, the child regained some upper extremity muscle power (coinciding with some improvement in spinal imaging showed in Figure 4), but still remained profoundly weak in his lower extremities.