Primary cardiac lymphoma: autopsy case report and literature review.

Primary cardiac lymphoma (PCL), defined as extranodal non-Hodgkin's lymphoma involving exclusively the heart and∕or pericardium, is a neoplasm with an extremely low incidence, a high degree of malignancy, and a poor prognosis. It comprises 0.5% of all extranodal lymphomas and 1-2% of all primary cardiac tumors, while the most commonly reported subtype is diffuse large B-cell lymphoma (DLBCL). The tumor is more common in immunocompromised patients compared with those who are immunocompetent. Modern imaging methods now allow for earlier detection of these tumors, despite their variable clinical manifestation, which is often a cause of misdiagnosis. We present an autopsy case of undiagnosed PCL in an immunocompetent 72-year-old man, where postmortem examination revealed massive tumor infiltration of the right-sided heart chambers extending to the left ventricle. Histological analysis showed microscopic tumor infiltration within the left atrium as well. A diagnosis of DLBCL of non-germinal subtype was made based on immunohistochemistry.