Cerebral amyloid angiopathy: A clinicopathological study of three cases

Cerebral amyloid angiopathy (CAA) is an important cause for intracerebral hemorrhage (ICH), yet often goes undiagnosed in the absence of histological examination of the blood vessels in the clot. In this study, we report three patients who presented with ICH. Two patients had no risk factors for bleed, whereas one patient had systemic hypertension. Tissue for analysis was obtained during hematoma evacuation in two patients and necropsy in the third. Histopathology in all three patients revealed severe degree of amyloid angiopathy with extensive amyloid deposits in the vessel walls, which was diagnostic of CAA. Both medium- and small-sized leptomeningeal and cortical vessels were affected. The vascular amyloid deposits stained with Congo red and displayed characteristic birefringence under polarizing light. In addition, vessels also showed fibrinoid necrosis and vascular endothelial proliferation. Immunohistochemistry demonstrated beta-amyloid peptide in all three cases—the protein most commonly involved in sporadic CAA. Senile plaques with amyloid cores were present in all areas, whereas neurofibrillary tangles were restricted to the medial temporal region in the autopsied case. CAA is an important cause for intracerebral bleed and may be a contributory factor even when other risk factors for ICH are present. Areas of hemorrhage tend to correlate with severity of CAA changes.