A 35-year old female presents to the outpatient clinic with a chief complaint of left lower extremity swelling and heaviness. She first noticed this approximately one month ago and the swelling has gotten progressively worse over that time. It is acutely worse with exercise. On exam, her left thigh and calf are noticeably larger than the right with mild pitting edema without extension onto the foot or toes. She denies any history or family history of thromboembolism or thrombophilia. A left lower extremity venous duplex is performed and spectral Doppler of the left common femoral vein is shown below. The remainder of the venous study shows compressible deep venous structures with flow throughout.

Figure 1. Duplex Doppler of the left common femoral vein. Click for larger image

Click below to take the self-evaluation quiz for this case. After successfully passing the quiz you can view explanatory notes about the choices as well as references for further reading before proceeding to the next case.