Pathology
H&E
The patient proceeded to re-resection.
Histology
MICROSCOPIC DESCRIPTION: The sections show small areas with features of high grade astrocytoma. These show dense hypercellularity, marked nuclear and cytoplasmic pleopmorphism, multilayering of atypical cells around microvessel lumena and areas of necrosis. No immunostaining for MGMT is seen in tumour cell nuclei. Topoisomerase labelling index: Approximately 10%
The majority of the specimen, however, shows florid reactive gliosis and neovascularisation (not hyperplastic microvascular proliferation as seen in tumour) and areas of infarct-like necrosis (bottom left corner). Nuclear MGMT staining is preserved in these areas (note the tumour was methylated, thus this is suggestive or normal cells) and the features are most consistent with post irradiation/post-chemotherapy effect.
DIAGNOSIS: Recurrent glioblastoma IDH-1 wild type with florid reactive changes most consistent with post-irradiation/post-chemotherapy effect.