Cardiac Pseudotumor Simulated by Ascitic Pseudocyst: Cross-sectional Imaging Findings of a Rare Complication of Peritoneovenous Shunting

摘要

A 63-year-old woman undergoing treatment of metastatic chondrification to liver, lung, and peritoneum presented with a history of refractory ascites. A peritoneovenous (Denver) shunt was placed, and 2 months later, a chest and abdominal outpatient CT scan was performed for restaging. A large fluid-attenuation mass within the right atrium in contact with the tip of a peritoneovenous shunt was revealed (Fig 1), new since a previous CT scan performed 1 month before. Cardiac MRI confirmed the presence of a right atrial mass extending from a stalk originating from the posterior atrial wall with predominantly fluid signal and no late gadolinium enhancement (Fig 2). Differential diagnosis included thrombus, necrotic metastasis, and ascitic pseudocyst. The lesion was removed surgically, and a solid cystic mass associated with chylous material and organizing thrombus and negative for malignancy was described.