Bronchogenic Cyst Presenting as Acute Pericarditis.

Bronchogenic cysts are speculated to arise from abnormal budding of the foregut tissue during embryogenesis. Around 90% of mediastinal bronchogenic cysts are asymptomatic, and a small percentage of them present with chest pain and dyspnea. Pericardial effusion is one of the manifestations described; however, pericarditis has not been widely reported. We describe a case of a bronchogenic cyst in a 19-year-old female with an initial presentation of pericarditis due to mechanical impingement. There was an associated trace to small pericardial effusion. The bronchogenic cyst was planned to be excised; however, it could only be partially excised due to its adherence to the left atrium.