Thomas G. DeLoughery, MD, FACP, FAWM

Oregon Health Sciences University, Portland, OR

This case was reviewed and updated in October 2012 by Dr. Alvin H. Schmaier and members of the Teaching Cases Subcommittee.

Copyright of the American Society of Hematology, 2006. ISSN: 1931-6860.


Leg swelling can be caused by several processes. In all patients with unilateral leg swelling, thrombosis must be considered first, since untreated outcomes are life threatening. However, other local entities also have to be considered in the diagnosis. These include local blockage of venous return that can be due to lymphadenopathy, tumor masses, pregnancy, hernias, etc. One can also see leg swelling as part of generalized edema such as that found in heart failure or liver disease; however, in these latter cases, the edema is bilateral. Inflammation of the skin can lead to leg swelling. The most common cause of this is cellulitis, but it can also be seen with vasculitis processes such as erythema nodosum. Other etiologies for unilateral leg edema include chronic venous stasis disease associated with leg discoloration, ruptured Baker cyst, and soft tissue tumors. Rare conditions include congenital absence of lymph channels (Milroy’s syndrome), arterial-venous fistulas, and vascular hemangiomas such as Klippel-Trenaunay syndrome.

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