Cerebral amyloid angiopathy (CAA) with presentation as a brain inflammatory pseudo-tumour.

Cerebral amyloid angiopathy (CAA) is frequent but often asymptomatic. It can induce lobar haemorrhage, rapidly progressive dementia or recurrent transient neurological symptoms, other presentations being less frequent. We report 3 patients in their sixties presenting with a space occupying lesion which was the first manifestation of CAA. They were operated with a diagnosis of cerebral tumour. In all three cases, macroscopy was similar, the lesions were superficial in the cerebral cortex and the preoperative diagnoses were glioblastoma, meningioma and cavernoma. Histologically, the lesions consisted of a large inflammatory granuloma with numerous lipophages and siderophages surrounding capillaries with prominent endothelial cells. Vessels in the near cortex and meninges and within the granuloma harboured heavy amyloid deposits immunolabelled by anti-P component, anti-protein beta A4 with a A40 predominance and anti-apolipoprotein E. Adjacent cerebral cortex showed reactive gliosis and rare senile plaques. Amyloidosis is rarely considered among diagnoses of space occupying lesions. In our three cases, CT scan and MRI changes were related to the presence of an inflammatory granuloma around foci of haemorrhage and amyloid laden vessels.