[Pleuropericardial cyst rupturing into the pericardium causing tamponade].

Pleuropericardial cysts of the mediastinum are rare lesions, usually congenital but exceptionally acquired. They are often asymptomatic, but complications can occur. We report below the case of a 35-year-old man who presented with an acquired right-sided para-tracheal mesothelial cyst that ruptured into the pericardium and was responsible for clinical tamponade. Although the majority of mesothelial cysts are asymptomatic, only a strict clinical and radiological follow-up can provide an indication for surgical resection. This should be reserved for symptomatic patients or for those facing an uncertain diagnosis.