Arterial compression of the right common iliac vein; an unusual anatomical variant.

Compression of the left common iliac vein by the right common iliac artery has been well described (Cockett's syndrome). The authors describe a case report of compression of the right common iliac vein by the right internal iliac artery. The patient presented with ipsilateral lower limb oedema. Venography showed smooth extrinsic compression of the right common iliac vein. The CT scan was initially interpreted as showing no extrinsic mass or obvious compressing lesion and lymphography was normal. It was the duplex scan which showed the bifurcation of the right common iliac artery crossing the right common iliac vein and causing significant extrinsic compression.