Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 4 2 2019 08 06 48 51 EN Behshad Pazooki Department of Internal Medicine, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. Alborz Sherafati Department of Cardiology, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2018 12 27 2019 03 18 Pulmonary embolism is a serious complication occurring in different cancers. Patients who have cancer may have complications like brain metastasis or pericardial effusion, which may change the therapeutic management of pulmonary embolism. In this article, a patient is presented with lung adenocarcinoma resulting in pericardial effusion. He was admitted with pulmonary embolism and atrial flutter, which made his management difficult. https://crcp.tums.ac.ir/index.php/crcp/article/view/246 https://crcp.tums.ac.ir/index.php/crcp/article/download/246/314