Histomorphological diagnostic features to consider
| Tissue/Histopathology | Consider in diagnosis |
|---|---|
| Endocardium | |
| Fibrosis | Organised thrombus |
| Healed biopsy site | |
| Myocardial infarct | |
| Healed acute rejection site | |
| Graft procurement injury | |
| Adjacent prosthetic device | |
| Abnormal blood flow haemodynamics | |
| Hypereosinophilic syndrome | |
| Mastocytosis | |
| Endocardial fibroelastosis | |
| Healed myocarditis | |
| Cardiomyopathy | |
| Drug toxicity | |
| Ulceration/necrosis | Adjacent prosthetic device |
| Healing biopsy site | |
| Hypereosinophilic syndrome | |
| Myocardium | |
| Hypertrophy | Hypertrophic/dilated cardiomyopathy |
| Pressure/volume overloaded ventricle | |
| Storage disorders | |
| Primary myopathies (Duchenne’s/Becker’s) | |
| Muscular dystrophies (myotonic) | |
| Fibre disarray | Hypertrophic cardiomyopathy |
| Healed biopsy site | |
| Ventricular apex | |
| Junction of free wall and interventricular septum | |
| Interstitium | |
| Fibrosis | Healed biopsy site |
| Myocardial infarct | |
| Healed acute rejection site | |
| Adjacent prosthetic device | |
| Hypereosinophilic syndrome | |
| Mastocytosis | |
| Healed myocarditis | |
| Cardiomyopathy | |
| Drug toxicity | |
| Lymphocytes | Allograft rejection (focal or diffuse) |
| Quilty lesion (A or B) | |
| Normal allograft (sparse and diffuse) | |
| Myocarditis/dilated cardiomyopathy | |
| Post transplant lymphoproliferative disease | |
| Lymphoma | |
| Leukaemia | |
| Neutrophils | Bacterial/fungal endocarditis (±necrosis) |
| Fulminant acute allograft rejection | |
| Fulminant myocarditis | |
| Hypereosinophilic syndrome (+eosinophils) | |
| Sepsis | |
| Eosinophils | Hypereosinophilic syndrome (Loeffler’s) |
| Hypersensitivity (for example, drug) | |
| Fulminant allograft rejection | |
| Parasitic infection (Chagas) | |
| Granulomas | Sarcoidosis |
| Amyloidosis | |
| Aschoff nodules | |
| Foreign body reaction | |
| Giant cell myocarditis | |
| Intramural vessel changes | Allograft vasculopathy |
| Hypertrophic cardiomyopathy | |
| Systemic arterial hypertension | |
| Amyloidosis | |
| Collagen vascular disorders | |
| Mitral valve prolapse |









