BACKGROUNDSecondary cardiac involvement by lymphoma has received limited attention in the medical literature, despite its grave prognosis. Although chemotherapy improves patients’ survival, a subgroup of treated patients dies suddenly due to myocardial rupture following chemotherapy initiation. Reducing the initial chemotherapy dose with dose escalation to standard doses may be effective in minimizing this risk but the data are limited. We report on the successful management of a patient with disseminated diffuse large B-cell lymphoma (DLBCL) involving the heart using such approach.CASE SUMMARYAn 18-year-old male presented to our hospital with six months history of progressive dyspnea, orthopnea and cough. On physical examination, the patient was found to have a plethoric and mildly edematous face, fixed elevation of the right internal jugular vein, suggestive of superior vena cava obstruction, and a pelvic mass. Investigations during admission including a thoracoabdominal computed tomography (CT) scan with CT guided biopsy of the pelvic mass, echocardiography and cardiac magnetic resonance imaging led to the diagnosis of disseminated DLBCL with cardiac involvement. The patients were successfully treated with chemotherapy dose reduction followed by dose escalation to standard doses, under the guidance of cardiac imaging. The patient completed chemotherapy and underwent a successful bone marrow transplant. He is currently in remission and has a normal left ventricular function.CONCLUSIONImaging-guided chemotherapy dosing may minimize the risk of myocardial rupture in cardiac lymphoma. Data are limited. Management should be individualized.