Primary Cardiac Lymphoma Diagnosed and Subtyped on Pericardial Fluid Cytology

Abstract

Primary cardiac lymphoma (PCL) is a very rare malignancy, involving only the heart/pericardium with no or minimal evidence of extra-cardiac involvement. A 73-year-old lady presented with dyspnea on exertion. Echocardiography revealed a mass predominantly involving the right atrium with moderate pericardial effusion. Pericardiocentesis was done and the smears showed a monomorphic population of medium-sized atypical lymphoid cells. Immunohistochemistry performed on the cellblock was suggestive of Diffuse large B cell lymphoma (DLBCL), activated B cell (ABC) type. PET-MR revealed a metabolically active large diffusely infiltrative intracardiac mass lesion with no other distant possible sites of primary malignancy or extracardiac deposits. Thus, a diagnosis of PCL was made. She underwent a single fraction of palliative radiotherapy as she was unfit for definitive chemotherapy. Cytological evaluation of pericardial fluid using cell block is a useful and effective tool in the diagnosis as well as subtyping of PCL presenting as malignant effusion.