MICROSCOPIC DESCRIPTION:
The sections show a densely hypercellular glial tumour centred in white matter and extending focally into overlying cortex. Tumour cells are markedly pleomorphic with variably shaped, large vesicular nuclei, many with conspicuous nucleoli. An occasional mitotic figure is identified. No endothelial cell hyperplasia is seen and there is no necrosis. Moderate numbers of tumour cells have foamy, xanthomatous cytoplasm. Scattered multinucleated tumour giant cells are also noted. Prominent perivascular cuffing by small lymphocytes is noted in several areas of the tumour. Tumour cells, including those with xanthomatous features, show strong immunostaining for GFAP and nestin. The features are of pleomorphic xanthoastrocytoma (PXA). The topoisomerase labelling index is approximately 5%.
DIAGNOSIS:
Pleomorphic xanthoastrocytoma (PXA) - WHO Grade II.