ACUTE PERICARDITIS IN A PATIENT WITH PRIMARY HEART LYMPHOMA

A 51–year–old male patient was admitted to the emergency room for stabbing chest pain associated with dyspnea on mild exertion. Past medical history: obesity, previous HCV infection, previous intravenous substance abuse. Physical examination: no audible cardiac murmurs or rubs, no wet lung sounds, mild edema of the face and upper limbs. ECG: sinus rhythm, no repolarization alterations. Lab tests: elevation of troponin I (93 ng/l) and CRP (2 mg/dl). Echocardiogram (poor visualization): non–dilated and normokinetic left ventricle (EF 0.55), no significant valvular disease, mild pericardial effusion. Coronary angiography: no obstructive coronary disease. A diagnosis of acute pericarditis was made, and anti–inflammatory therapy with ibuprofen and colchicine was started. Cardiac MRI showed a large right atrial mass, which infiltrates the interatrial septum and causes obstruction of the superior vena cava; the mass showed hypointensity on T1, clear hyperintensity on T2 and modest and non–homogeneous late gadolinium enhancement; mediastinal lymphadenopathy was also detected; overall, the exam raised the suspicion of malignant primary cardiac tumor (cardiac lymphoma versus angiosarcoma). The patient was referred to a tertiary center for endomyocardial biopsy, which showed the presence of large B–cell lymphoma, and the patient was started on chemotherapy. Discussion Cardiac masses are rare and usually benign. Malignant tumors are more frequently secondary, while primary ones are very rare. Lymphomas represent 1–2% of all cardiac tumors, are more frequent in male adults and are associated with immunodeficiency conditions. 70% are diffuse large B–cell lymphomas. Transthoracic echocardiogram is the main first–level test but has poor sensitivity, especially in cases with high acoustic impedance. Cardiac MRI is the main test for accurate anatomical definition and tissue characterization. In this specific case, the hyperintensity in the T2 sequences, the presence of inhomogeneous LGE and the mediastinal lymphadenopathy suggested the possible lymphoproliferative nature of the mass. Angiosarcoma appears more heterogeneous on T2 sequences and presents a ring of peripheral enhancement with central hypopointesity in post–contrast sequences. Endomyocardial biopsy allows for a definitive diagnosis, but is performed only when the benefits outweigh the risks. In this case, it proved to be essential for the histological characterization and the subsequent therapeutic approach.