A biopsy was obtained from the periventricular part of the mass. Histopathology report follows:

High grade glioma compatible with glioblastoma, IDH-wildtype, WHO grade 4.

A small fragment from a neoplasm composed in part from small mononuclear cells and in part from large cells with extensive eosinophilic cytoplasm and cytological atypia. Mitotic activity seen. Necrotic foci seen. Inconclusive microvascular proliferation. The cells are not arranged in any particular order. Scattered stromal calcifications. Immunohistochemical staining: positive for olig2, GFAP; negative for IDH1, EGFR, H3K27M, NF, SYN, and KERMNF116. Staining for ATRX was negative (loss of expression). Very few scattered cells stained positive for p53. ~10% of cells were positive for Ki67.

A ventriculoperitoneal shunt (VPS) was inserted into the left ventricle.

Pineal region glioblastoma is exceedingly rare.