Presentation
Gradual onset leg weakness.
Patient Data
Abnormality in the thoracic spinal cord extends from T4 to T9. Complex cystic septated and multiloculated mass in the dorsal spinal cord involves T6-T7 disc to mid T9 level over 6 cm craniocaudal length. Cystic component is largest at proximal T9 measuring 12 x 11 mm (ML x AP). This expands the spinal cord effacing subarachnoid CSF. Mild to moderate enhancement in the nodular rim component anteriorly at T8-T9 (4 x 8 mm axial dimension) with smaller areas of rim enhancement with nodularity at mid T8 level. Amorphous small volume rim enhancement at T7. No avid enhancement. Small areas of reduced T2 signal and fluid/fluid level suggests previous hemorrhage. No other intramedullary lesion. Inferior to the cystic component there is non-enhancing low T1 high T2 signal along the dorsal columns most likely edema and extends from inferior T9 to mid T10 level. At the superior aspect of the mass, T4 to T6 there is a small dorsal cleft of signal abnormality but no definite mass.
The biopsy shows very limited tissue with an aggregate of glial cells.These cells are unevenly distributed. No perivascular pseudorosettes or true rosettes are seen. The glial cells have mildly enlarged and hyperchromatic nuclei, small nucleoli and scanty cytoplasm. Elsewhere, there are some pigmented macrophages, suggestive of previous hemorrhage. No mitoses, microvascular proliferation or necrosis is identified. The tumor cells are GFAP positive. There is EMA perinuclear dot positivity in the cells (black arrows in Figure 1), in keeping with ependymoma. The Ki-67 index is 1%. IDH-1 immunostain is negative.
DIAGNOSIS: Ependymoma (WHO Grade II).