Unusual case of left iliac vein compression secondary to May-Thurner syndrome and crossed fused renal ectopia.

External compression of the left iliac vein against the fifth lumbar vertebra by the right iliac artery May and Thurner syndrome is a well-known anatomic variant. We identified a rare case of May-Thurner syndrome associated with crossed fused renal ectopia on the left side. The patient presented with complete thrombosis of the left common iliac vein down to the popliteal vein. He was treated with catheter directed thrombolysis followed by anticoagulant therapy.