Pembrolizumab induced pericardial tamponade: A case report.

Pembrolizumab is an immune checkpoint inhibitor used in various types of cancers. Pericardial tamponade is a rare side effect reported in only very few case reports. Early recognition and therapeutic intervention is vital in all cases. We report a case of a 54-year-old male with Stage 3 lung adenocarcinoma who developed cardiac tamponade secondary to pembrolizumab and subsequently required pericardial window.