Cardiac Amyloidosis - XII

Foreign body giant cell reaction to amyloid deposits in the heart.  A.  Myocardial amyloid deposits are seen in the center of the field, as well as some multinucleated giant cells and histiocytes.   It is difficult to see amyloid deposits inside the giant cells. (H&E X400). B. Immunohistochemical staining for transthyretin shows a deeper section of the field shown in A and distinctly shows a multinucleated giant cell with transthyretin positive material in its cytoplasm.  The extracellular amyloid is also clearly positive for transthyretin.  (Transthyretin immunohistochemistry, X400)

The ultrasctructural diagnosis of amyloid starts with examination of the 1 µm thick plastic embedded sections prepared to map the electron microscopic sections to be cut.