A case of epicardial cyst.

A rare case of epicardial cyst diagnosed at surgery was presented. A 64-year old woman was admitted for evaluation of a mediastinal mass shown by echocardiography to be adjacent to both ventricles. Computed tomography (CT) and magnetic resonance imaging (MRI) studies were performed. On CT, there was evidence of an abnormal mass lesion at the lateral side of the outlet of the right ventricle. The CT number of the mass was 24.7, suggesting cystic lesion. MRI revealed that the intensity of the lesion signal was higher than that of subcutaneous fat on the T2 weighted image. On the T1 weighted image, a low intensity was identified in the same region. During operation a mass originating from the epicardium was diagnosed as an epicardial cyst.