May-Thurner Syndrome, a Frequently Overlooked Cause of Iliofemoral Vein Thrombosis.

May-Thurner syndrome (MTS) involves the compression of the left iliofemoral vein by the right common iliac artery against the vertebral body, creating an environment conducive to venous stasis and endothelial injury, which predisposes patients to deep vein thrombosis (DVT). Although often asymptomatic, MTS can present with lower extremity swelling and claudication. We present a case of a 72-year-old female who developed extensive left lower extremity DVT. Imaging studies, including Doppler ultrasound and venography, confirmed the diagnosis of MTS with significant vessel occlusion. Treatment involved mechanical thrombectomy, angioplasty, and iliac vein stenting. The patient demonstrated rapid symptom resolution post-procedure and was discharged on anticoagulation therapy. This case underscores the importance of recognizing anatomical factors like MTS in patients with DVT and highlights the role of interventional management in preventing complications.