Cardiac Amyloidosis

Figure A. H&E x20

Figure B. H&E x40

Figure C. Trichrome stain x20

Figure D. Trichrome stain x40

Figure E. Congo Red stain x40

Figure F. Electron Microscopy

Figure G. Electron Microscopy



Clinical History: 68 year-old male with 5 year history of restrictive cardiomyopathy, who had multiple episodes of syncope. His kappa: lambda free L/C ratio was found to be 0.42 (n 0.58-2.24).

Histology: A heart biopsy was performed and H&E sections (Figures A & 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 fibrillary material (Figure G) consistent in size and appearance with amyloid (n 5-15 nanometer).

(Last Edition: May 22, 2018 )