The patient underwent a stereotactic right frontal craniotomy and resection of the tumour.
MICROSCOPIC DESCRIPTION: Paraffin sections show a densely hypercellular glial tumour composed predominantly of pleomorphic oligodendroglial cells with a quantitatively smaller population of astrocytic cells. Numerous minigemistocytes and gliofibrillary oligodendrocytes are also present. Scattered mitotic figures are identified as well as foci of vascular endothelial cell hyperplasia. No necrosis is seen. Tumour is well demarcated from adjacent white matter. Perineuronal secondary structuring is prominent in adjacent cortex. An area of dystrophic calcification is present within the adjacent brain parenchyma. The features are of anaplastic oligoastrocytoma.
FINAL DIAGNOSIS: Anaplastic oligoastrocytoma WHO Grade III