Case report: Marantic endocarditis: A multidisciplinary case in which the etymology helps to determine the aetiology

Background Non-bacterial thrombotic endocarditis (NBTE), also known as ‘Marantic’ endocarditis, is a rare and life-threatening condition that involves thrombotic thickening of cardiac structures, most often heart valves, with the potential to cause multiple embolisms. In the literature, NBTE has been reported in association with advanced malignancies, connective tissue disease (CTD) and inflammatory disorders. We present a case of Marantic endocarditis (ME) related to Acute Promyelocytic Leukemia (APL) causing visceral organ infarction, notably splenic, renal and brain, without the development of major sequelae. Case summary We report a case of a 43-year-old male with a history of bicuspid aortic valve and aortic coartation, surgically corrected at an early age, was presented to our service showing signs of deep vein thrombosis, disseminated intravascular coagulation (DIC), and multiple signs of embolism. During diagnostic evaluation, a non-bacterial thrombotic vegetation was identified on the aortic valve and an early relapse of APL was confirmed. The patient was treated with a standard regimen for APL and anticoagulation therapy. On close follow up, we observed a reduction in the size of the vegetation without structural cardiac damage and further signs of thromboembolism. Discussion As highlighted, in the emerging literature, the presence of multiple systemic emboli, whether cutaneous or involving visceral organs, should prompt clinicians to evaluate for endocarditis and distinguish between infective and non-infective causes. This is particularly essential in setting of malignancy or systemic inflammatory state. The present case underscores the importance of the timely recognition of Marantic endocarditis in all cases presenting with disseminated intravascular coagulation, in order to prevent further escalation. In addition, it offers an opportunity to reinforce the understanding of pathophysiological mechanisms and open the window for new insights and further reflections.