Histology
MICROSCOPIC DESCRIPTION: Paraffin sections show fragments of a moderately hypercellular tumour composed of cells with uniform round and oval nuclei with finely granular chromatin and delicate processes. These are arranged in diffuse sheets and perivascular pseudo-rosettes. No mitotic figures are seen and there is no vascular endothelial cell hyperplasia and no necrosis. Myxoid-mucinous material is noted in some of the pseudo-rosettes interposed between the central blood vessel and the surrounding corona of tumour cells. Tumour cells show strong immunostaining for GFAP. Weak staining for epithelial membrane antigen (EMA) is noted in some pseudo-rosettes. The features are of myxopapillary ependymoma. The Ki-67/MIB-1 labelling index is <1%. 4. The section shows a dense collagenous membrane covered on one surface by tumour with features as described in specimens 1-3. No nerve tissue is identified.
FINAL DIAGNOSIS: Myxopapillary ependymoma.(WHO Grade I)