A 35-year-old Moroccan man presented with pain in the upper left abdomen for one day. He had a 13-year history of high-dose albendazole treatment for inoperable cystic cardiac echinococcosis and dilated, but stable cardiomyopathy. Physical examination demonstrated a visible and palpable mass pulsating synchronous with every heartbeat in the left upper abdomen (Supplementary Video 1). Cardiac magnetic resonance imaging with contrast enhancement (Panel A: axial view, Panel B: coronal view of Fig. 1) demonstrated progression of pericardial Echinococcus granulosus cysts over a trajectory of 18 cm with breakthrough into the abdominal cavity. [...]