Inferior vena cava (IVC) agenesis is a rare congenital disease in which venous return from the lower limbs is achieved through collateral veins, mainly thorough the azygos and hemiazygos veins [1]. Most IVC agenesis patients are asymptomatic, but they occasionally present with venous thromboembolic events (VTE). In fact, the incidence of congenital IVC malformations in young patients with lower limb deep venous thrombosis (DVT) has been described between 5 and 16% [2–5]. We previously reported clues to diagnosis of IVC agenesis in patients with VTE.
