Cardiac lymphomas are rare extranodal lymphomas involving primarily and secondarily the heart and/or pericardium. Here we describe three cases of cardiac involvement from lymphoma with specific peculiarities: two primary cardiac Diffuse Large B-cell Lymphomas and one secondary involvement from Marginal Zone Lymphoma (MZL). The first case highlights the issue of early CNS relapse and the possible role for CNS prophylaxis; the second case demonstrates the difficulties of interpretation and possible mistakes of different radiologic techniques adopted to evaluate cardiac involvement by lymphoma during follow-up; the third is a unique case of MZL with cardiac involvement. Our aim is to share the findings observed in these cases putting them in relation with data from the literature.