MICROSCOPIC DESCRIPTION:
1&2. The sections show unremarkable dura mater and pia arachnoid. No specific diagnostic abnormality is seen in either specimen. In particular, there is no inflammatory cell infiltration and no evidence of tumour is seen.
3. The sections show two cores of cerebral white matter. These show several foci of rarefaction of myelin in perivascular white matter. Mononuclear inflammatory cells are noted within perivascular spaces. These are predominantly CD3+ T lymphocytes. The surrounding white matter shows reactive gliosis and there is microglial activation. CD68+ monocyte-macrophages are also noted within perivascular spaces as well as the T lymphocytes. Immunostaining for SV40/BK virus is negative. The features are strongly suggestive of acute disseminated encephalomyelitis (ADEM). No evidence of tumour is seen.
4. The sections show cerebral cortex with overlying leptomeninges. Cortical laminar architecture is preserved. No dysplastic features or evidence of malformation of cortical development are seen. Immunostaining for A beta protein is negative. The leptomeninges are unremarkable with no inflammatory cell infiltration seen.
DIAGNOSIS:
- Dural biopsy: Unremarkable dura.
- Arachnoid: Unremarkable pia arachnoid.
- Left frontal white matter: Features strongly suggestive of acute disseminated encephalomyelitis (ADEM).
- Cortical surface: Unremarkable cerebral cortex and leptomeninges.