The patient went on to have a biopsy of the lesion.
Histology
MICROSCOPIC DESCRIPTION: The section shows very small fragments of moderately hypercellular tissue. In several fragments there are hypercellular areas composed of cells with moderate nuclear pleomorphism. Cells in these areas show strong immunostaining forGFAP, indicating astrocytic lineage, and an elevated Ki-67/MIB-1 labelling index (approximately 8%). No mitotic figures or areas of necrosis are seen. Thin-walled vessels are noted in some fragments. No vascular endothelial cell hyperplasia is seen. The features are strongly suggestive of astrocytoma.
FINAL DIAGNOSIS: Spinal cord astrocytoma.