The patient went onto have the clot evacuated and a small sample of tissue sent to histology.
Sections show abundant fresh blood clot, containing layers of degenerating neutrophils and fibrin alternating with red cells. There is accumulation of blood beneath the leptomeninges, which contain scattered vessels of varying calibre showing mural thickening with some luminal narrowing, and amorphous eosinophilic material within the wall that is strongly suggestive of amyloid. Congo red stains this material, which shows apple green birefringence on polarisation.
A small fragment of oedematous cortex and white matter is sampled. This shows a mild astrocytosis. Only small capillary-sized vessels are seen, however these are normal in appearance. There is no evidence of a vascular malformation.
FINAL DIAGNOSIS: Intracerebral haematoma, cortex over frontal cerebral haematoma and leptomeningeal vessels showing amyloid angiopathy.
feature images from this case