A Rare Anatomical Venous Variant in the Lower Extremity.

We describe a rare venous anatomical variant identified in a 68-year-old male with lung cancer and deep vein thrombosis (DVT). Color duplex ultrasonography revealed direct drainage of the popliteal vein into the common femoral vein, with absence of the superficial femoral vein. This previously undescribed variation may have contributed to thrombogenesis in the hypercoagulable setting of malignancy. Recognition of such variants is essential for accurate diagnosis and appropriate management of DVT.