[An unusual pericardial tumor: bronchogenic cyst].

The authors report the case of an intrapericardial bronchogenic cyst in a 42 year old woman with no cardiac symptoms. Despite extensive investigation, the final diagnosis was made only at anatomopathological examination. A pericardial localisation of this embryological tumour is very rare and a number of features of the condition are described. In this case, the carbohydrate antigen (CA 19-9) was a veritable marker of this tumour. This association, described for the first time, between a simple biological marker and an intrapericardial bronchogenic cyst, could be a valuable diagnostic aid in a pathology in which surgery could reasonably be deferred should the diagnosis of bronchogenic cyst be certain.