Thrombus or vegetation?Importance of cardiac MRI as a diagnostic tool based on case report and literature review

Introduction We report the Case of a 35 years old male patient admitted for pulmonary embolism in a febrile context. Transthoracic echocardiography showed a filamentary mass appended to the pulmonary valve whose thrombotic origin has been suggested on data of late gadolinium enhancement magnetic resonance imaging. Case presentation The patient had a history of deep vein thrombosis in the context of familial thrombophilia with factor V leiden gene mutation in two of his sisters and an inhaled drug addiction to heroïn. There was a biological inflammatory syndrome with negative blood cultures. Transthoracic echocardiography showed a very mobile homogeneous hyperechoic mass measuring 8 cm in the right ventricle appended between the pulmonary valve and the lateral wall of the RV. In LGE-MRI, an isointense, to the myocardium, marginal hall and a central rim enhancement were objectified, suggesting the diagnosis of thrombus rather than vegetation. Conclusion Despite the notion of drug addiction, the febrile context and the localization of the mass, a diagnosis of RV thrombus rather than infective endocarditis was favored relying on familial thrompbophilia, personal history of DVT and LGE-MRI aspect. The patient was treated with curative heparin therapy and antibiotic therapy. Due to the persistence of the mass after three weeks of treatment and after heart-team discussion, the patient underwent surgical mass removal. The anatomopathological study confirmed a fibrino-cruoric thrombus.

Highlights • Differential diagnosis between thrombus and vegetation is sometimes a real challenge for the clinician. • Cardiac MRI with its LGE-MRI sequences can help characterizing thrombus with hypointense edges and brighter central zone called “the etched appearance”. • Even in the multimodality imaging era, anatomopathological stady sometimes is needed to reach the correct diagnosis.