[Mediastinal pseudo-tumor from portal hypertension (author's transl)].

A radiological opacity of the posterior and inferior mediastinum should evoke a lesion of vascular origin. The venous nature of the mass can be easily confirmed by morphological changes apparent during the respiratory cycle and changes in position. Investigations to establish etiology of this venous ectasia arising from the azygos vein require more extensive radiological examinations, and computed tomography may be of value. Portal hypertension is one cause of increased venous blood flow in the azygos systems, and should be systematically considered.