Glioblastoma IDH wildtype and demyelination

Within the left superior temporal gyrus, there is a 2.5 x 2.6 x 2.3 cm rim enhancing-enhancing lesion - localising to a grey-white interface rather than the cortex. The lesion is heterogeneous on T1 and T2 weighted sequences with moderate diffusion restriction identified throughout. On susceptibility imaging, a complete hypointense rim is not identified. There is increased rCBV within the enhancing portion of the lesion.

Spectroscopy demonstrates elevated lactate peak and markedly depressed NAA within the non-enhancing central portion of the lesion. At the periphery of the lesion, there is moderate NAA reduction, but choline peak assessment is limited by a wandering baseline.

There is extensive surrounding white matter T2 hyperintensity in keeping with vasogenic oedema. There is resultant mass-effect with effacement of the left temporoparietal sulci and minor effacement of the left lateral ventricle. No hydrocephalus or midline shift. The basal cisterns are preserved.

No other lesion identified.

Conclusion:

Peripherally enhancing mass within the left superior temporal gyrus with surrounding vasogenic oedema.The The main differential is between metastasis and GBM.

Although there is diffusion restriction of the lesion, this is not isolated to the central non-enhancing component, and the thick irregular rind favours tumour over abscess.

MICROSCOPIC DESCRIPTION:

The sections show densely hypercellular tissue fragments composed of of a mixture of CD68+ monocyte macrophages and astrocytic cells which show show moderate to marked nuclear and cellular pleomorphism. Both cell types types are arranged in diffuse sheets. There is prominent microvascular proliferation proliferation with multilayering of endothelial cells which also show nuclear nuclear and cellular pleomorphism. Endothelial cell mitoses are noted.

There are a moderate number of Creutzfeldt astrocytes. Mitotic figures are are identified in atypical atrocytic cells. A fragment of necrotic tissue tissue is present with neutrophilic infiltration of the immediately adjacent adjacent viable tissue. Collections of CD3+ lymphocytes are noted within within and adjacent to the walls of some blood vessels. Extensive loss loss of myelin is identified in a Luxol Fast Blue stained section and granular granular LFB+ material is seen in the cytoplasm of macrophages. Preservation of axons is seen in a Bodian stained section.

IMMUNOHISTOCHEMISTRY:

• GFAP positive in atypical and reactive astrocytes and
• Creutzfeldt cells.
• Nestin positive
• IDH-1 negative
• p53 positive
• p16 negative

Topoisomerase labelling index: Approximately 12%

FINAL DIAGNOSIS:

Left temporal lesion: Features favouring glioblastoma multiforme(WHO Grade IV)

COMMENT:

These are difficult biopsies to interpret with apparent overlapping features features of demyelination (loss of myelin on Luxol Fast Blue staining, axonal preservation, perivascular T lymphocyte aggregation; the presence of of Creutzfeldt astrocytes) and high grade-grade astrocytoma (astrocyte pleomorphism pleomorphism, mitotic figures, microvascular proliferation and necrosis necrosis).