Pathology
H&E
H&E
H&E
H&E
MACROSCOPIC DESCRIPTION: A nodule of gelatinous pale tan tissue 28x22x12mm.
MICROSCOPIC DESCRIPTION: Paraffin sections show a circumscribed moderately hypercellular tumour. This is composed of a mixture of nucleus-rich and poor regions, the latter being composed of tumour cell processes. Tumour cells have uniform round and oval nuclei with an open chromatin arrangement. No mitotic figures are seen and there is no vascular endothelial cell hyperplasia and no necrosis. Occasional poorly formed perivascular pseudorosettes are identified. Tumour cells show strong immunostaining for GFAP (not shown). No staining for epithelial membrane antigen (EMA) or synaptobrevin is seen (not shown). The features are of subependymoma. The topoisomerase (not shown) labelling index is approximately 1%.
DIAGNOSIS: Intraventricular tumour: Subependymoma (WHO Grade I)