MICROSCOPIC DESCRIPTION: The sections show fragments of cerebral cortex and white matter. There is extensive replacement of the white matter by a moderately hypercellular astrocytic glioma. This consists of diffuse sheets of predominantly protoplasmic astrocytes. These have regular small round hyperchromatic nuclei and a paucity of fibrillary processes. A very occasional mitotic figure is identified. There is prominent microcyst formation. A gemistocytic component is noted in one area. There is no vascular endothelial cell hyperplasia and no evidence of necrosis is seen. The features are of protoplasmic/gemistocytic diffuse astrocytoma (WHO grade II).
DIAGNOSIS: Frontal brain tumour: Protoplasmic/gemistocytic diffuse astrocytoma (WHO grade II).