[Pericardial cyst, a rare, minimally symptomatic lesion easy to treat].

A pericardial cyst is a rare and benign lesion, most commonly of congenital origin. A female patient of 35 years old was admitted to the emergency department of our institution, for non-irradiating thoracic pain associated with a dyspnea. A CT-Scan was performed, and a pericardial cyst of a large size was found. A surgical procedure through thoracoscopy was performed to enhance the symptomatology of the patient and to eradicate the cyst. The diagnosis of these lesions is most commonly sporadic after a radiography performed for other causes. Most of the time these lesions are asymptomatic (although thoracic pains, chronic cough and dyspnea amongst others may be observed). In case of suspicion (related to radiography or an eventual symptomatology) a thoracic scan is performed with a contrasting product for the confirmation and localization of the cyst. In addition to the diagnosis and the localization, it is best to perform a transthoracic ultrasound which enables a differential diagnosis with other lesions (lipoma, aortic aneurysm, solid tumour, and a left ventricle aneurysm etc.). A surgical treatment is recommended in symptomatic cases. In non-symptomatic cases, a transthoracic ultrasound is recommended.