[Superior vena cava syndrome disclosing dissection of the aorta].

The authors report a case of dissection of the aorta presenting as a superior vena cava syndrome. Because of the rarity of such a manifestation, this dissection was not suspected before CT scan. A review of the literature confirms the rarity of obstruction of the superior vena cava during dissection and indicates that it results from a compressive hemomediastinum. In this case, the superior vena cava was compressed by the ascending aorta itself, which had become very large but had not ruptured into the mediastinum. This forms the basis of the originality of the case.