This is different than leptomeningeal gliomatosis:
Diagnosis:
Suggested by MRI and confirmed by pathology (brain biopsy/resection)
Pathology:
Gross: enlarged brain, diffusely. Involving white matter more than grey matter, may involve any part of the neuroaxis, diffuse tumor without a single large mass
Histology: infiltration of grey & white matter by undifferentiated cells. Elongated cells, forming parallel rows when infiltrating tracts. No microvascular proliferation.
Immunohistochemsitry: GFAP positive variably.
Findings on Investigations:
CT:
- Homogenous, hypodense, loss of grey white junction, swollen hemispheres. Low sensitivity.
MRI:
- Involvement of the grey matter and some of the white matter, swollen hemispheres with sulcal effacement
- T1: hypointense or isointense.
- T2: hyperintense. Better than T1.
- Minimal enhancement.
- Overall low sensitivity.
Treatment:
Radiation therapy