Patient Data
Limited sagittal images (digitized printed film) demonstrate an enhancing mass below the conus, associated with a fatty filum terminale.
MICROSCOPIC DESCRIPTION: The sections show a moderately cellular tumor, forming perivascular pseudorosettes. The tumor cells form cuffs around blood vessels. There is mucoid material in-between the blood vessels and the tumor cells. The tumor cells have mildly enlarged ovoid nuclei and small nucleoli. Mitoses are inconspicuous. There is no microvascular proliferation or necrosis. The tumor cells are GFAP positive. The Ki-67 index is 1%. They are EMA negative. The features are those of myxopapillary ependymoma.
DIAGNOSIS: Spinal tumor: Myxopapillary ependymoma (WHO Grade I).
Case Discussion
Spinal myxopapillary ependymomas are a variant type of spinal ependymoma that occur exclusively in the conus medullaris and filum terminale.
Fatty filum terminale is a relatively common finding on imaging of the lumbar spine, and in most cases is an incidental finding of no clinical concern.