Cardiac tamponade and myocardial infarction (MI) are rare as the initial presentation of a malignancy. ST-elevation myocardial infarction (STEMI) and cardiac tamponade have been described to present together in the setting of a type-A aortic dissection causing coronary malperfusion. We describe a case with an atypical presentation of an MI due to a thrombus in the right coronary artery occurring simultaneously with a pericardial effusion causing tamponade physiology, related to malignancy. We present this unique case of MI and cardiac tamponade as it was not caused by a type-A aortic dissection. We suggest that malignancy be considered in the differential diagnosis when these findings present together.