[Diagnostic considerations in a case of pericardial effusion with anomalous distribution].

The authors report an atypical arrangement of pericardial effusion simulating an expansive mediastinal mass. Radiologic examination of the chest (standard, fluoroscopy and conventional tomography) failed to establish the correct diagnosis, its diagnostic aid was only related to demonstrate the lesion, without provided any additional anatomical and morphological features. The final and correct diagnosis was only obtained with CT and U.S. These latter imaging modalities have correctly located the lesion in pericardial space, and particularly they identified it like an loculated, completely fluid pericardial not corpusculated effusion. The authors remarked the value of CT and US techniques in the study of para and pericardial regions, especially of pericardial serosal surfaces. CT scan allow to localize the lesion, and to discriminate through densitometric values between cystic and solid masses; further more it provided information of possible extracardiac and/or mediastinal invasion. US provides the features of the fluid, its changes during systo-diastolic cycle, its mobility in different patient positions and the thickness of cardial wall. Nevertheless, at present, we consider both imaging modalities indispensable in the study of lesions occupying the cardiac-mediastinal border.