ABSTRACT
A 57-year-old man with a history of right pneumonectomy for squamous cell lung cancer who presented with dyspnea and hypotension, was found to have pericardial effusion complicated by cardiac tamponade, associated with pembrolizumab therapy. Pericardiocentesis could not be safely attempted due to presence of right-sided mediastinal tissue shift in the setting of previous right pneumonectomy. The patient improved significantly with surgical placement of pericardial window. Analysis of the pericardial fluid was negative for malignancy and was consistent with acute inflammation. Pembrolizumab and other immune checkpoint inhibitors are associated with cardiovascular toxicity, including pericardial effusion and in rare cases, cardiac tamponade. Treatment of cardiac tamponade in post-pneumonectomy patients may be subject to anatomical limitations precluding percutaneous pericardiocentesis and requires early recognition as well as availability of surgical intervention.