Infrahepatic inferior vena cava agenesis with bilateral renal vein thrombosis.

Congenital anomalies of the inferior vena cava (IVC) are rare and are estimated to be present in 0.07-8.7% of the general population. IVC agenesis (IVCA) is found in approximately 5% of cases of unprovoked lower extremity deep vein thrombosis in patients <30 years of age. Renal vein thrombosis (RVT) is an extremely rare and unusual presentation of IVCA. We report a unique case of a 23-year-old previously healthy man presenting with infrahepatic IVCA-induced bilateral RVT with azygos and hemiazygos continuation. To our knowledge, this is the third reported case in the literature of IVCA-induced RVT and the first to affect the bilateral renal veins in the absence of any other thrombogenic risk factors or any lower extremity venous complications. We also present a literature review of IVCA-induced vein thrombosis and highlight the lack of literature to manage this condition.