Lymphangiosarcoma, or Stewart-Treves Syndrome (STS), is a very rare skin angiosarcoma with poor prognosis, which usually affects the upper limbs of patients who underwent breast cancer surgery, including axillary dissection followed by radiotherapy (RT). Cutaneous lymphangiosarcomas, which account for approximately 5% of all angiosarcomas, usually originate in the limb with chronic lymphedema. Lymphatic blockade is involved in the onset of STS. RT contributes indirectly to an increased risk of developing STS by causing axillary-node sclerosis and resulting in a lymphatic blockade and lymphedema. Chronic lymphedema causes local immunodeficiency, which indirectly leads to oncogenesis. Currently, axillary nodes are no longer routinely irradiated after axillary dissection, which is associated with a reduction in the incidence of chronic lymphedema from 40% to 4%. The use of sentinel lymph node biopsy technique is also widespread and the associated risk of lymphedema is further reduced. Thus, the incidence of STS decreased significantly with improved surgical and radiation techniques. The overall prognosis of STS patients is very poor. Only early radical surgical removal, including amputation or disarticulation of the affected limb, or wide excision at an early stage offers the greatest chance of long-term survival. Only a few case reports and series with a small number of patients with lymphangiosarcoma can be found in the literature. We present a case report of the first diagnosed STS at our department in an effort to highlight the need of the consideration of developing lymphangiosarcoma in patients with chronic lymphedema.

Department of Dermatovenereology Charles University Prague Faculty of Medicine and University Hospital in Pilsen Edvarda Beneše 13 305 99 Pilsen Czech Republic

Department of Imaging Methods Charles University Prague Faculty of Medicine and University Hospital in Pilsen alej Svobody 80 304 60 Pilsen Czech Republic

Department of Oncology and Radiotherapy Charles University Prague Faculty of Medicine and University Hospital in Pilsen alej Svobody 80 304 60 Pilsen Czech Republic

Sikl's Department of Pathology Charles University Prague Faculty of Medicine and University Hospital in Pilsen Edvarda Beneše 13 305 99 Pilsen Czech Republic Bioptical Laboratory Mikulášské nám 4 326 00 Pilsen Czech Republic