We describe the case of an 18-year-old patient with no history of disease who was admitted to our hospital due to multiple trauma after a motorcycle accident.
He presented left costal fractures, cardiac and pulmonary contusion and hemothorax requiring pleural drainage.
After the acute phase, the chest X-ray showed a well-defined rounded image in the left upper lobe, which was not present before the trauma, which was initially interpreted in relation to residual tissue injury after trauma.
After discharge, the radiological image remained unchanged.
One month later, in a routine outpatient check-up, when the patient was asymptomatic, the chest X-ray revealed a marked increase in the cardiac silhouette, in addition to a rounded image, which was invariable.
Physical examination and electrocardiogram were normal.
Transthoracic echocardiogram showed severe pericardial effusion without signs and cardiac tamponade.
A computed tomography scan showed pericardial effusion and a cystic image located in the left upper lobe, which was located in the pericardium.
Treatment was started with nonsteroidal anti-inflammatory drugs, and three weeks later, pericardial effusion was present in a new control echocardiogram.
A study of the pericardial effusion was carried out in order to exclude another origin different from that probably due to the existence of communication with the pericardial cyst.
Mantoux was negative, and blood count, coagulation, and complete blood and urine biochemistry, including proteinogram, electrophoretic study, viral and bacterial serology, autoimmune battery and thyroid hormones were normal causes and others thyroid effusions.
Examination of the cyst by nuclear magnetic resonance confirmed the presence of a rounded homogeneous cystic lesion of 5.4 x 8 centimeters located in the anterior mediastinum, located to the left of the upper lobe and on the left apical segment.
The cyst was connected to the pericardium by a length, and was reported as a pericardial cyst.
Due to the good evolution, we opted for patient follow-up and not to take invasive attitudes.
The patient was asymptomatic during follow-up.
In the current control magnetic resonance imaging, cystic image remains unchanged.
