Pathology of endomyocardial biopsy

Endomyocardial biopsy (EMB) is routinely performed for cardiac transplant monitoring. Moreover, it can be a useful tool in the diagnostic work-up of myocarditis, cardiomyopathies, drug toxicity, unexplained arrhythmias, heart involvement in systemic disease, and to diagnose cardiac masses. Pathologic evaluation of EMB represents the gold standard in specific disorders, including myocarditis and cardiac involvement by amyloidosis and sarcoidosis. To increase the diagnostic yield of the procedure, multiple myocardial samples should be obtained, and processed in a fully-equipped laboratory, with access to immunohistochemical/histochemical analyses, molecular tests and transmission electron microscopy. We here review the main diagnostic features of myocarditis, cardiomyopathies and cardiac tumours on EMB, specifying the ancillary techniques required to reach the diagnosis in each specific cardiac disease.