Intra-cardiac thrombus formation and histopathology of the ventricular tissue in I+G heart. (A and B) Heart cross-section at the papillary muscle level of the LV from iron (I) only (A and C) and I+G heart (B and D) stained with Masson's trichrome and Prussian blue staining, respectively. Note that the formation of a large mural thrombus in I+G heart. (E and F) Obvious fibrosis near the endocardium was noted in the I+G heart (F), but not in the iron only group (E). (G and H) Higher magnification of the LV from I+G group depicted regions of prominent fibrosis between thrombus and myocardium (G) and macrophages with cytoplasmic iron (brown color) deposition, infiltrated into intra-cardiomyocytic spaces (H). (I) Magnification of thrombus near the LV papillary muscle demonstrated leukocytes (arrows) involved in thrombus formation. Tissue section in E was stained with iron staining; tissue section in F, G, H, and I were stained with H & E staining.