[Cardiac Diffuse Large B-Cell Lymphoma Presenting with Acute Heart Failure Due to Cardiac Tamponade].

A 75-year-old man was admitted to our hospital in May 2016 with progressive shortness of breath. We considered him to be experiencing acute heart failure caused by atrial fibrillation. Contrast-enhanced computed tomography showed a hypodense mass involving the right atrium and left ventricle, pericardial effusion, and lymphadenopathy of the groin. Histological finding from the groin and pericardial effusion analysis showed diffuse large B-cell lymphoma(DLBCL). We thus diagnosed this patient with cardiac tamponade owing to the involvement of the heart by DLBCL. Treatment was initiated with tetrahy- dropyranyldoxorubicin/cyclophosphamide/vincristine/prednisolone(THP-COP)therapy(50% dose)and continuous pericardial drainage. We carefully added rituximab 4 days after monitoring his symptoms and vital signs. There were a few adverse effects, and after treatment, the mass and pericardial effusion disappeared. Subsequently, 8 courses of THP-COP therapy accompanied by rituximab(R-THP-COP)(full dose)were administered, resulting in a complete response.