P589A not so simple pericarditis

Funding Acknowledgements: none A 62-year-old male, with no other clinical history than arterial hypertension, referred to our Emergency Department (ED) at the beginning of August 2017 due to fatigue, dry cough and chest pain experienced during the previous 3 days and fever during the previous 2 days. At admission, he was haemodinamically stable, temperature was 37.1°C, his EKG showed sinus tachycardia, PR segment depression and diffuse ST-T segment abnormalities; chest radiogram was unremarkable. A transthoracic echocardiogram showed mild circumferential pericardial effusion without other abnormal findings; at blood tests, C-reactive protein was 17,34 mg/dL (n.v.<0,5) and troponine I was 132 ng/L (n.v.<40). He was then admitted to Cardiology Unit and treated with ibuprofen and colchicine with fast symptoms resolution; discharge was made after 3 days with diagnosis of acute peri-miocarditis. At the end of September 2017, patient referred again to our ED due to dyspnea and palpitations that occurred after ibuprofen withdrawal. A new echocardiogram showed moderate pericardial effusion and an isoechogenic right atrial mass, adherent to the free atrial wall and extending to tricuspid annulus with a maximum diameter of 21 mm, and a right ventricular free wall thickening (maximum 28 mm) just below the tricuspid valve. Patient was then admitted to our Cardiac Intensive Care Unit; cardiac MRI confirmed the presence of an abnormal myocardial thickening at right atrial and right ventricular free wall level, with diffuse involvement of the atrioventricular (AV) groove, surrounding the right coronary artery; interatrial septum seemed also to be involved; the mass resulted hypointense at the perfusional sequences and inhomogeneous after gadolinium injection; moderate circumferential pericardial effusion and pleural effusion were present. Clinical presentation and MRI findings allowed us to hypothesize the presence of a cardiac lymphoma; a subsequent whole body PET-CT scan with 18-FDG showed an isolated abnormal uptake at the cardiac mass level. 72 hours after the admission, patient developed also a high grade AV block. Endomyocardial biopsy was performed and histological examination confirmed the presence of a Giant B-cell non Hodgkin isolated cardiac lymphoma (very rare as it represents 1-2% of primitive cardiac tumours, which are per se a rarity). Chemiotherapy according to R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) treatment protocol was promptly started with AV block resolution at day 6; at day 11 the mass was not anymore evident at transthoracic echocardiogram. Cardiac MRI at 6 months showed no evidence of masses and patient was free from disease after 15 months of follow-up. Abstract P589 Figure. CMR images