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).