[Cerebral amyloid angiopathy presenting as a pseudotumor: 2 cases with spontaneously favorable outcomes].

A rare clinical and radiographical presentation of cerebral amyloid angiopathy mimicking a brain neoplasm was observed in 2 patients. The signs and symptoms included seizures and focal parieto-occipital dysfunction in 1 case, massive left hemisphere dysfunction and akinetic mutism in the other. Brain CT and MRI showed nonspecific focal white matter abnormalities suggestive of the diagnosis of low-grade glioma. Gradient echo T1 and T2-weighted images showing multiple areas of signal void suggesting multiple disseminated petechial hemorrhages led to the diagnosis of cerebral amyloid angiopathy. An eventless brain biopsy confirmed the diagnosis. The neuropathology examination disclosed amyloid angiopathy of the pial and cortical vessels selectively stained by anti A-beta protein antibodies. The clinical course was remarkable in the two cases with almost complete clinical recovery without any particular treatment.