A rare anatomical variation of the deep femoral vein with aneurysm: a case report with clinical significance.

We present a rare anatomical variation of the deep femoral vein (DFV) originating from the popliteal vein (PV) with an associated aneurysm. The DFV arose from the PV at the adductor hiatus, exhibited an aneurysm, and coursed upward through the fourth osseo-aponeurotic opening of the adductor magnus muscle to enter the anterior thigh compartment before draining into the femoral vein. This unique variation likely resulted from developmental deviations during intrauterine life. The anomalous origin and aneurysm of the DFV may potentially cause venous hemodynamic disturbances, chronic venous insufficiency, increased risk of deep vein thrombosis, and potentially life-threatening pulmonary embolism. Anatomical variations of the DFV in terms of origin, course, or termination are rare but clinically relevant, especially in the context of vascular surgeries, imaging, and interventional procedures involving the femoral region. This case highlights the importance of recognizing venous anatomical variations and their clinical implications.