The Hematoxilin & Eosin (H&E) sections (Figures A
and B) show myocardial tissue with
unremarkable cardiomyocytes and mild to moderate interstitial fibrosis, confirmed by trichrome staining
(Figures C and D). The small vessels show moderate wall thickening with
accumulation of smudgy, light eosinophilic material with cracking appearance,
which stains light purple with the trichrome staining.
Congo red staining (Figure E) viewed under
polarized light shows apple-green birefringence consistent with amyloid
deposits. Electron microscopic examination (Figures F and G) reveal
cardiomyocytes and vascular structures surrounded by a fibrillar material
(Figure G) consistent in size and appearance with amyloid.
December 13, 2019