"Cavernous malformation": A portion of cerebral cortex 17x13x13mm with a small amount of possible white matter at one aspect. Centrally there is a congested and microcystic lesion 10mm in maximum dimension.
Fig 1: The sections show a nidus of small calibre vascular channels which is sharply demarcated from surrounding white matter. Vessels have a back-to-back arrangement with no intervening brain parenchyma. The vessel walls are composed of collagen with no smooth muscle or elastic tissue identified.
Fig 2 (left): The immediately adjacent white matter is gliotic and contains scattered collections of haemosiderin-filled macrophages. Extracellular aggregation of haemosiderin is also noted. The features are of a cavernous haemangioma. No evidence of tumour is seen.
Fig 2 (right): Perls' stain for iron and shows hemosiderin in macropahes and a blue blush which is extaracellular iron that has not formed discrete granules. This is likely to be hemotoidin.
Sections not shown:
"Lateral neocortex" (not shown): A portion of lateral temporal lobe measuring 40x35x15mm (superior-inferior x posterior margin-temporal pole x superficial surface-deep margin) with preserved and unremarkable appearing superior, middle and inferior temporal gyri.
MICROSCOPIC DESCRIPTION: The sections of temporal neocortex show preserved cortical lamination. No features of malformation of cortical development are seen. Moderate numbers of neurons are noted in white matter. Myelination appears normal. There is no evidence of tumour.
"Hippocampus" (not shown): A segment of hippocampus 20mm long with attached mesiotemporal white matter.
MICROSCOPIC DESCRIPTION: Serial sections of hippocampus shows preserved numbers of neurons in all CA sectors. Numbers of neurons are also preserved in the dentate fasciculus with no evidence of dispersion. No evidence of tumour is seen.