Lower Extremity Angiosarcoma: A Life-Threatening Complication of Lymphedema.

When angiosarcoma, a rare and aggressive tumor of the soft tissue, develops in the setting of chronic lymphedema, it is referred to as Stewart-Treves syndrome. It is usually seen in chronic lymphedema of the upper limbs postmastectomy. Angiosarcoma developing in the lower limb in the setting of chronic lymphedema is rare and has a poor outcome. The presentation of angiosarcoma can vary, ranging from a bleeding papule to a plaque or a subcutaneous mass, which can later progress to ulceration or necrosis. Treatment for Stewart-Treves syndrome is aggressive because of its poor prognosis and usually requires a multidisciplinary approach of surgery, radiation, and chemotherapy. Several theories have been put forth to explain the mechanism of Stewart-Treves syndrome, but it remains ambiguous. The current literature regarding angiosarcoma developing in the setting of chronic lymphedema in the lower limb is limited to single case reports. Herein, the authors report a series of six cases of biopsy-proven angiosarcoma in the setting of lower extremity lymphedema. Providers should include angiosarcoma in the differential diagnosis of ulcerative or vascular tumors arising in the context of lower extremity lymphedema.