Case report:
This 27-year-old right-handed patient first presented with a homonymous hemianopsia and signs of increased intracranial pressure. The CT of the brain scan showed the right intracranial parietal and occipital expansive tumor responsible for an internal falcorial and temporal herniation. Due to clinical signs and symptoms consistent with raised intracranial pressure, she underwent urgent maximal debulking surgery, with post-operative scans demonstrating near-total resection.
Histopathological examination of the resection specimen showed dense tumor proliferation consisting of layers of cells with a high nucleo-cytoplasmic ratio and little cytoplasm. Mitotic figures were easily identified, including necrosis (figure 1).
Cells show immunohistological staining for synaptophysin and CD56. (Figure 2)
Staining for cytokeratin, TTF-1, INMSI, neurofilament, GATA3, SSTR2A, and chromogranin-A was all negative. Glial markers (Olig2 and GFAP) were also negative, and the protein INI-1 was positive in approximately 60% of tumor cells. The histological findings were considered to be most consistent with CNS-PNET, WHO grade IV, now known as a CNS embryonal tumor (NOS).