Abstract
BACKGROUND: Primary cardiac lymphomas are extremely rare entities (< 2% of cardiac tumours) and the most frequent histologic type is diffuse large B-cell lymphoma (DLBCL). Fibrin-associated DLBCL (FA-DLBCL) is a very unusual form of DLBCL associated with chronic inflammation, and only case reports and small series have been described. In the heart, it usually occurs in the context of a cardiac myxoma or cardiac prostheses and it is not bulk forming. These lymphomas frequently present with non-germinal center phenotype and are associated with Epstein-Barr virus (EBV) type III latency. CASE PRESENTATION: We describe a case of FA-DLBCL arising in a cardiac myxoma, with plasmacytic differentiation and type I EBV latency. CONCLUSIONS: Although they are very rare, FA-DLBCLs should be known for their diagnostic difficulty, due to its unspecified clinical manifestations, and for their more favourable prognosis, sometimes even without additional treatment after surgical resection.