Pericardial cysts are rare, benign lesions of the pericardium, usually situated on the right or left cardiophrenic angles. Bidimensional echocardiography shows them as hypoechogenic, quite spheric masses starting from pericardium and usually associated with different grades of pericardial effusion. Clinicians must put pericardial cysts in the differential diagnosis of mediastinal masses.
These masses are usually well tollerated but may occasionally be symptomatic when cause a compression of contiguous structures (main bronchus, vascular structures, right-sided heart chambers). A very rare but threatening complication is the rupture of the cyst in the pericardium with subsequent tamponade.
Pericardial cysts are usually an incidental finding on chest x-ray. The diagnostic work-up include: echocardiography for the differential diagnosis with other diseases (i.e. left ventricle aneurysm, aortic aneurysm, solid tumors), for the evaluation of the anatomic relations with other cardiac structures and for the assessment of possible complications (i.e. compression of surrounding structures); three-dimensional and transoesofageal echocardiography may help in a better determination of the mass; TAC and MRI could provide a more precise characterization of the lesion and its relation with mediastinal structures.
1. Patel J, Park C, Michaels J, Rosen S, Kort S. Pericardial cyst: case reports and a literature review. Echocardiography. 2004 Apr;21(3):269-72.
2. Butz T, Faber L, Langer C, Wiemer M, Horstkotte D, Piper C. Images in cardiovascular medicine. Echocardiography-guided percutaneous aspiration of a large pericardial cyst. Circulation. 2007 Oct 30;116(18):e505-7.