Deep venous thrombosis caused by inferior vena cava atresia and hereditary thrombophilia.

Inferior vena cava (IVC) atresia is a risk factor for deep vein thrombosis (DVT) in young patients. Although Doppler ultrasound diagnoses DVT, a contrast-enhanced computerized tomography (CT) or magnetic resonance angiography (MRA) diagnoses IVC atresia, other congenital IVC anomalies and must be considered in young patients presenting with idiopathic DVT. Patients with IVC atresia associated with hereditary thrombophilia are at increased risk for recurrent DVT and may require long-term anticoagulation. We report 2 cases: the first one, a 33-year-old man with lower extremity DVT caused by IVC atresia in association with multiple thrombophilic risk factors; the second one, a 34-year-old woman with lower extremity DVT caused by IVC atresia in association with prothrombin gene mutation. To our knowledge, this association has not been reported. The clinical presentation, tools for diagnosis, and the need for long-term anticoagulation are discussed.