[Temporary exertion-dependent paresthesias in agenesis of the inferior vena cava].

A 23-year-old man with agenesis of the inferior vena cava (IVC) and azygos continuation had progressive, temporary, activity-dependent paraesthesias of the legs which developed after increasing sports activity as a soldier. The diagnosis was made from the chest X-ray (enlarged azygos shadow) and the computed tomogram (retro- and para-aortic space-occupying structures representing the enlarged collaterals draining the lower half of the body). There are at present no known therapeutic measures for this very rare anomaly. Management thus focuses on the prevention of complications, such as thromboses in the distal drainage channels.