fig1

Figure 1. Endomyocardial biopsy diagnosis of cardiac amyloidosis: (A) traditional hematoxylin–eosin stain with evidence of eosinophilic interstitial deposits between cardiomyocytes; (B) Heidenhain trichrome stain highlighting amyloid in pale blue; (C,D) Congo red stain under light microscopy (C) and polarized light microscopy (D) with the typical apple-green birefringence; (E) immunohistochemical typing positive for TTR fibrils; and (F) thioflavin-T staining showing fluorescence in dark-field microscopy upon binding to amyloid fibrils. (A-F) Original magnification,× 100.