In April 2004, a 58-year-old immunocompetent man was hospitalised for atrial flutter and dyspnoea. An electrocardiogram and echocardiography were performed and showed a large pericardial effusion, with diastolic collapse of the right atrium. A diagnostic pericardiocentesis yielded 800 ml of blood-stained fluid. Cytological analysis did not show any neoplastic cells. The patient was discharged with non-steroidal anti-inflammatory therapy without a definitive diagnosis. In March 2005, he was hospitalised again with cough and severe dyspnoea. His general clinical condition was rapidly worsening and his performance status was poor. Chest radiography showed an enlarged cardiac profile. Echocardiography demonstrated a small pericardial accumulation, considered to be clotted blood. The initial clinical and radiological diagnosis was haemorrhagic pericarditis with cardiac tamponade. However, a computerised tomography (CT) scan showed a large intra-pericardial mass, also involving the sternum and ribs (top). A thoracotomy was performed and a tumour surrounded by sero-haemorrhagic fluid was identified. Histological examination demonstrated the presence of large malignant cells. The immunophenotype was: CD45+, CD20+, CD79a+, CD3−, CD10−, BCL6−, BCL2+, CD30−, MUM1/IRF4+, CD38+, IRTA1−, MPO−, CD117−, CD68/PGM1−, CD34− and terminal deoxynucleotidyl transferase negative. The proliferation/MIB1 expression was 90%. There was monotypic kappa light chain expression. The presence of Epstein–Barr virus (EBV) RNA was excluded by in situ hybridisation for EBV-encoded RNA 1/2. A diagnosis of diffuse large B-cell lymphoma (DLBCL), immunoblastic, with activated B-cell phenotype, was made (bottom). Total body CT-scan, positron emission tomography and bone marrow biopsy did not identify any other site of disease. The only biochemical abnormality was an elevated lactate dehydrogenase level (1559 UI/L). Chemotherapy according to the CHOP-Rituximab scheme (cyclophosphamide, doxorubicin, vincristine, prednisone and rituximab) supported by pegylated filgrastim was promptly administered leading to a rapid and progressive improvement. After six courses of therapy the patient was asymptomatic. Two months later, echocardiography and CT scan demonstrated the complete resolution of the pericardial effusion. Cardiac involvement by malignant lymphoma is a rare but well-known condition, representing approximately 1·3% of cardiac tumours and 0·5% of extra-nodal non-Hodgkin lymphoma (NHL). The clinical behaviour is usually aggressive and the more frequent early symptoms are cardiac failure, syncope, arrhythmia and pericardial effusion.
Malignancy must be excluded in every case of acute pericardial disease and NHL should be always considered in the differential diagnostic spectrum of cardiac tumours.