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Prominent left pelvic, inguinal, and proximal lower extremity vascular malformation. The left common femoral artery and left common femoral vein are markedly dilated with an apparent fistulous connection. The veins draining into the left femoral vein in the adductor and vastus lateralis regions are prominent. The left common iliac and left external iliac arteries are prominent and tortuous. The left external iliac and left common iliac veins are markedly dilated; the left common iliac vein appears to communicate with the distal abdominal aorta at the region of the aortic bifurcation. The left common iliac vein appears to drain into a duplicated inferior vena cava at the left side of the abdominal aorta, which further drains into the left renal vein. The hepatic segment of the normal right-sided inferior vena cava and the hepatic veins are prominent. The rest of the normal right-sided inferior vena cava is intact in caliber. The internal pudendal veins and prostatic venous plexus are prominent. The abdominal aorta is intact in caliber. 

3D volume rendering image shows the duplicated inferior vena cava and complex pelvic-inguinal vascular malformation.