heart lymphoma (MONDO_0003917) is an extranodal lymphoma that arises from the heart and/or the pericardium. The majority of the cases are diffuse large B-cell lymphomas. Patients may present with chest pain, heart failure, pericardial effusion, arrhythmia, or syncope. Also known as: Cardiac lymphoma, PCL, Primary heart lymphoma, lymphoma of heart, lymphoma of the heart, primary Cardiac lymphoma.