Fatal Cardiac Tamponade Due to a Pericardial Inflammatory Myofibroblastic Tumor

The patient was a 34-year-old woman who suddenly collapsed. On arrival, she was in cardiac arrest. Cardiac ultrasound revealed cardiac tamponade; thus, urgent thoracotomy with pericardiotomy was performed. Spontaneous circulation was temporarily obtained; however, her circulation was not stabilized, and she ultimately died. An autopsy revealed a pericardial inflammatory myofibroblastic tumor (IMT) causing bloody cardiac tamponade. There were no signs of cardiac rupture, myocardial infarction or aortic dissection. We reported the first case of fatal bloody cardiac tamponade due to pericardial IMT in an adult. An autopsy is important for clarifying the etiology in cases of fatal cardiac tamponade of unknown cause.