[Idiopathic retroperitoneal fibrosis with large vessel thrombosis].

A 53-year-old female was hospitalized for evaluation of swelling in the bilateral lower extremities. A computed tomography (CT) scan of the abdomen revealed bilateral hydronephrosis and features consistent with retroperitoneal fibrosis. Transfemoral venography and magnetic resonance angiography (MRA) showed thrombosis of both the left common iliac vein and inferior vena cava, and filling of numerous collateral veins in the retroperitoneal area. A diagnosis of idiopathic retroperitoneal fibrosis with central venous thrombosis was made. Ureteral stenting, medication with corticosteroids and subsequent warfarin were started, resulting in marked improvement of renal function and the lower extremities. Diagnosis and follow-up of deep venous thrombosis can be aided by MRA. Administration of steroids with anticoagulation was considered to be successful in the case presenting with deep venous thrombosis caused by retroperitoneal fibrosis.