MICROSCOPIC DESCRIPTION: 1&2. Paraffin sections show fragments of a densely hypercellular tumour. This consists of a vesicular arrangement of markedly pleomorphic spindle cells which enclose aggregates of cells which have a more epithelioid morphology. These have pleomorphic vesicular nuclei and a variable amount of pale cytoplasm. Frequent mitotic figures are identified. Vessels are prominent in many areas of the tumour and there is multilayering of atypical cells around vessel lumena. There are also several small foci of necrosis.
DIAGNOSIS: 1&2. Left frontal brain tumour: Gliosarcoma (WHO Grade IV).