Cardiac Amyloidosis - XVI

Amyloid and collagen fibrils.  As shown in light microscopic sections (Figure 7 C) amyloid filaments as they accumulate the may infiltrate the normal extracellular matrix.  This image shows the edge of a myocyte.  The basal lamina is almost non visible as its electron density is similar to the 10 nm thick amyloid fibrils.  However the darker (more electron dense) collagen fibers are distinctly visible mixed in with the amyloid deposits.  They should not pose a diagnostic dilemma for the pathologist.