Fetal diagnosis of superior vena cava aneurysm

Superior vena cava aneurysm is a rare intrathoracic vascular lesion with only 27 cases reported in the literature. The majority are fusiform and can be associated with cystic hygroma due to the close embryonic relationship between lymphatic vessels and systemic veins. This is the first report of superior vena cava aneurysm diagnosed with fetal echocardiography in a fetus with a cystic hygroma. There is a need of a prospective registry to further delineate all aspects of this condition and establish the most appropriate therapeutic approach.