Acute thrombosis of ductus arteriosus aneurysm causing pulmonary artery occlusion in a neonate

Abstract A 9-day-old male neonate was admitted to our hospital because of an incidentally detected systolic murmur in his regular visit for skin jaundice at a local hospital. Echocardiography showed a large irregular mass located at the bifurcation of the main pulmonary artery (MPA), protruding into the lumen, causing bilateral stenosis and increasing flow velocity, with left PA of 3 m/s and right PA of 3.2 m/s, respectively (Panel A). Cardiac computed tomography (CT) revealed that the mass had homogenous density without contrast enhancement, making it difficult to distinguish from the surrounding thymus tissue (Panel B). For further evaluation, cardiac magnetic resonance (MR) was performed, demonstrating a well-defined lesion (approximately 20 mm × 9 mm) with a filling defect situated between the MPA and the descending aorta (DAO), The lesion was suspected to originate from the ductus arteriosus.