[A case of superior vena cava syndrome due to extensive venous thrombosis of an idiopathic nature].

A 37-year-old man was admitted with facial edema and right arm swelling. Venography, computed tomography and magnetic resonance imaging showed massive organizing thrombi in the superior vena cava and bilateral internal jugular as well as subclavian veins, and showed no mass lesions occluding the veins in the mediastinum. Angioscopy demonstrated a white thrombus at the entrance of the right subclavian vein. All results of blood coagulation tests were normal. The patient was diagnosed as having superior vena cava syndrome caused by idiopathic venous thrombosis. Anti-coagulant therapy with intravenous tissue plasminogen activator injection and continuous urokinase and heparin infusion into the thrombi through a catheter were not effective in lysing the thrombi. Collateral circulation gradually developed and his symptoms decreased. We decided to follow this patient on warfarin medication because of the difficulty in removing the thrombi surgically.