Fig. 1.

Meningovascular and ventricular amyloidosis associated with Tyr69His substitution in TTR. a Gross images demonstrating golden-brown discoloration of the leptomeninges of the cerebral hemispheres and the cisterns at the base of the brain. A coronal section of the brain demonstrates diffuse cortical atrophy, but very little hippocampal atrophy or ventricular dilatation. b A Congo red stain performed on the cerebral leptomeninges highlights the vascular and extravascular amyloid deposits (inset, Congo red under epifluorescence microscopy with Texas red filter; original magnifications of 40×). c Visualization of the Congophilic meningovascular amyloid under polarized light reveals the diagnostic apple-green birefringence (Congo red; original magnification of 40×). d Subpial amyloid deposits in the insular cortex (H&E; original magnification of 40×). e, f Subependymal amyloid deposits in the alveus (e; H&E; original magnification of 100×) and fornix (f; H&E; original magnification of 40×)