The patient went on to have a laminectomy and excision of the mass.
Histology
MICROSCOPIC DESCRIPTION: Sections show a moderately cellular glial tumour. The tumour comprises a mixed population of cells, some showing glial features with fibrillary processes, yet others displaying more epithelioid features. Perivascular pseudorosettes are a prominent feature. No mitotic figures are identified and there is no necrosis or endothelial cell hyperplasia. The tumour cells are strongly GFAP positive, show punctate dot like cytoplasmic staining for EMA, and membranous staining for CD99. The Ki-67 proliferative index is approximately 1%.
FINAL DIAGNOSIS: The morphological and immunohistochemical features are of an ependymoma (WHO Grade II)