Unilateral leg edema: is it always vascular?

Unilateral lower extremity edema below the knee commonly results from deep venous thrombosis, venous insufficiency, or lymphedema. The patient history, a physical examination, and lower extremity venous duplex ultrasound often reveal the underlying etiology, which is frequently of vascular origin. Presently described is the case of a 23-year-old patient who underwent a diagnostic work-up for unilateral leg swelling and was found to have a relatively uncommon cause of edema: lipedema. Lipedema is a disease characterized by subcutaneous adipose tissue deposition, and although diagnosed very rarely in general cardiology outpatient clinics, it has been demonstrated to be a cause of lower extremity edema in approximately one-fifth of cases in specialized clinics.