Presentation
Lower limb weakness.
Patient Data
MRI demonstrates a high T2, low T1, brightly enhancing mass located just below the conus, with prominent edema involving the conus. The mass appears intradural.
MICROSCOPIC DESCRIPTION: The sections show a moderately hypercellular tumor. This consists of ependymal cells arranged in well formed perivascular pseudo-rosettes. Myxoid material is present within the pseudo-rosettes. Tumor cells are arranged in diffuse sheets between pseudo-rosettes. No mitotic figures are identified and there is no vascular endothelial cell hyperplasia and no necrosis. The features are of myxopapillary ependymoma.
DIAGNOSIS: Myxopapillary ependymoma (WHO Grade I)
Case Discussion
The differential of such a mass is limited to a myxopapillary ependymoma, or a spinal schwannoma.
Low power accounts for the tumor's name, with the pseudo-rosettes mimicking papillary growth pattern.