[A case of atypical pericarditis].

Introduction: An acute viral pericarditis may reveal a congenital pericardial abnormality.
Case History: We report the case of a young man of 29 years in whom the development of rapidly progressive dyspnoea and fever led to the echocardiographic diagnosis of a pericardial tumour. The thoracic CT scan showed a mass arising in the superior mediastinum with no evidence of spread. Surgical exploration allowed the excision of a soft mutilobular mass adherent only to the aorta. Histological examination revealed an intrapericardial bronchogenic cyst.
Conclusion: After a review of bronchogenic cysts we point out the properties of this rare intra-pericardial localisation, one of which is the frequently observed secretion of CA 19-9.