Non-invasive diagnosis of a pericardial cyst. Combined use of M-mode echocardiography and computed tomography

The case of a left-sided pericardial cyst (PC) in a 24 yearold asymptomatic patient is presented. Review of previous chestX-rays indicated that the PC had developed within five years.The PC could be clearly identified by M-mode echocardiography(E); the pattern, however, was similar to that of a pseudoaneurysmof the left ventricle, the latter being an important differentialdiagnosis. Computed tomography (CT) showed not only the positionand size of the PC but allowed, based on attenuation values,a clear differentiation between a pseudoaneurysm and a cysticstructure filled with an aqueous solution. The combined useof E and CT seems to represent a valuable non-invasive toolin the diagnosis of abnormal configurations of the left ventricle.