Palpable, Ropelike Cord from the Left Medial Malleolus to the Groin

Palpable, Ropelike Cord from the Left Medial Malleolus to the Groin

A 56-year-old woman began to have pain and redness of the left leg the day after a six-hour car ride. Two days later she was found to have erythema and tenderness on the medial aspect of the left knee and moderate pitting edema of the left ankle.

What’s the Diagnosis ?