Fig. 3
Histological assessment of endomyocardial biopsy. A Hematoxylin and eosin stain (HE) with arrows pointing to areas of edema seen as myocyte separation and bubbly nature of the interstitium. B, C Immunostain for macrophages (CD68) shows presence of significant interstitial macrophages. D Immunostain for T lymphocytes (CD3) show scattered lymphocytes with no evidence of myocyte damage. E Immunostain for B lymphocytes (CD20) shows rare positive cells. F Immunostain for C4d stain, a complement marker is positive focally in rare subendocardial myocytes (arrow) consistent with ischemic necrosis, probably secondary to right ventricular strain. (Magnification: A–F, 200×)