Adventitial cystic disease of the external iliac vein presenting with deep venous thrombosis. A case report.

Adventitial cystic disease of the venous system is a rare occurrence with only 8 reported cases in the world literature. The most commonly involved segment has been the common femoral vein, resulting in luminal compromise and presenting with extremity swelling. Painless swelling of the right lower extremity in a 37-year-old man was diagnosed as iliofemoral thrombosis by duplex examination. Thrombolysis revealed smooth luminal defects of the external iliac vein, which prompted surgical exploration. Iliofemoral thrombectomy exposed multiloculated adventitial cysts of the distal external iliac vein. The preferred surgical intervention in the literature has been transadventitial or transluminal evacuation of the mucoid cysts with removal of cystic wall. These are excellent options when there is no associated venous thrombosis, wall thickening, or persistent venous stenosis after drainage. This is the first reported case associated with deep venous thrombosis. In this situation resection of the involved segment followed by venous reconstruction might be the preferred option.