[Extrinsic compression of the right atrium due to a mediastinal germ-cell tumor].

A patient with a mediastinal mass detected by plain chest roentgenogram is presented. The echocardiographic-Doppler examination and the computed tomography precise the gross nature and extent of the tumour and its anatomical location producing obstruction of the right atrium and modifying the blood flow pattern in this chamber. The serum tumour markers and the transthoracic biopsy confirm the diagnosis of primary mediastinal germ cell tumour.