We report the case of a 38 y old man with antiphospholipid syndrome an
d exceptionally extensive central vein thrombosis in the right interna
l jugular vein, superior vena cava, and both subclavian veins. In spit
e of intensive anticoagulation therapy there was only a partial respon
se. We suggest the MR angiography be the reference standard for diagno
sis in this type of patient.