Presentation
Progressive lower limb weakness and patchy sensory changes.
Patient Data
Partially cystic/solid lesion is identified at the T3 level. This lesion appears intradural extramedullary on the sagittal sequence but appears more intra-medullary on axials appearing to be centered posteriorly within the cord and eccentrically expands the cord at this level. The lesion extends a vertical length 1 vertebral body height. Central cystic component measures 1 cm. The solid component more inferiorly demonstrates diffuse mild homogeneous enhancement. No blood product seen on T2. No flow voids.
Multifocal slightly T1 hyperintense to cord, mildly enhancing soft tissue nodules also extend along the entire length of cord in the subarachnoid space. There is also diffuse mild leptomeningeal enhancement along the spinal cord.
The largest lesion located at T3 (blue arrow) is partially solid and partially cystic, and not clearly intra or extramedullary in location. It is associated with innumerable leptomeningeal deposits (yellow arrows).
MICROSCOPIC DESCRIPTION: Paraffin sections show fragments of organizing blood clot. Some of these contain small aggregates of cells with angulated hyperchromatic nuclei and delicate processes. These cells show strong immunoreactivity for GFAP. Scattered cells show perinuclear staining for epithelial membrane antigen. No mitotic figures are identified and there is no vascular endothelial cell hyperplasia and no necrosis. The topoisomerase labeling index is <1%
FINAL DIAGNOSIS: Spinal cord tumor: Features favoring diffuse astrocytoma (WHO Grade II)
Case Discussion
This case of pathologically proven diffuse astrocytoma of the spinal cord with extensive leptomeningeal disease demonstrates how hard it is to sometimes distinguish intramedullary from extramedullary masses.