The patient was submitted to a tumor stereotactic biopsy and the suspected diagnosis was confirmed by the histology.

Histology

MICROSCOPIC DESCRIPTION: The sections shows small fragments of a densely hypercellular glial tumor. This is composed predominantly of markedly pleomorphic astrocytic cells with fibrillary morphology. A quantitatively smaller component of pleomorphic oligodendroglial cells is also noted. Scattered mitotic figures are identified. There is focal microvascular proliferation with multilayering of atypical cells around vessel lumena. Areas of necrosis are also seen. These incorporate thin walled necrotic blood vessels.

IMMUNOHISTOCHEMISTRY:

• GFAP positive in tumor and reactive astrocytes; negative in oligodendroglial cells.
• NogoA positive in oligodendroglial cells, negative in tumor and reactive astrocytes.
• Nestin positive (high)
• IDH-1 R132H negative (not mutated)
• ATRX positive (not mutated)
• MGMT negative (likely methylated)
• p53 positive
• Topoisomerase labeling index: Approximately 40%. The features are of IDH-1 wild-type glioblastoma multiforme.

FINAL DIAGNOSIS:  IDH-1 wild-type glioblastoma multiforme (WHO Grade IV).

Note: Although this is tumor is entirely consistent with an IDH wild-type glioblastoma, immunohistochemical IDH1 R132H negativity does not categorically exclude a non-IDH1 R132H mutation. To be absolutely certain one would need to perform IDH sequencing. 

In this age-group the likelihood of such a mutation is remote.