Bilateral Deep Vein Thrombosis Associated with Inferior Vena Cava Agenesis in a Young Patient Manifesting as Low Back Pain.

Congenital absence of the inferior vena cava is a rare vascular anomaly, and most cases are asymptomatic. Nevertheless, patients with inferior vena cava malformations may have increased risk of deep venous thrombosis. Particularly, cases of bilateral deep venous thrombosis may arise owing to an insufficient collateral venous drainage from the lower limbs. We hereby describe a case of a previously healthy young male patient presenting with bilateral lower limb deep venous thrombosis as the initial clinical manifestation of congenital inferior vena cava agenesis. We conclude that in young patients presenting with deep venous thrombosis, especially when thrombosis occurs spontaneously, bilaterally, or recurrently, inferior vena cava anomalies should be thoroughly investigated and ruled out as appropriate.