A 40-year-old woman with history of hypothyroidism and tubal ligation presented with left lower-extremity pain and swelling. Duplex ultrasonography revealed extensive, occlusive deep vein thrombosis of the left iliac and femoral veins. Her risk factors for deep vein thrombosis included a 10 pack-year smoking history and extended hours of sitting at her desk at work over the preceding 2 weeks. She denied any history of previous thromboembolic disease, repeated …