Presentation
Known anaplastic astrocytoma grade 3. Worsening lower back pain.
Patient Data
Lumbar vertebral bodies have normal height, alignment, and signal intensity. Intervertebral discs have unremarkable appearances, minimal posterior disc bulge of L5/S1 with no associated nerve root impingement. Focal spine epidural lipomatosis at the level of L5/S1. Spinal canal and intervertebral foramina are overall capacious, with no significant stenosis. Post contrast images, in particular, the sagittal T1 fat sat, demonstrate diffuse nodular enhancement scattered through the cauda equina. Paravertebral soft tissues are unremarkable.
Case Discussion
The nodular enhancement along the cauda equina is most compatible with leptomeningeal metastases, which is rarely seen with high-grade gliomas.
This case has the diagnosis presumed based only on imaging appearances and the known history of a CNS primary tumor in treatment.