Angiosarcoma in primary lymphedema of the lower extremity--Stewart-Treves syndrome.

After a 20-year latent period an angiosarcoma developed in the edematous leg of a 74-year-old woman with primary lymphedema. A deep venous thrombosis of the leg which further aggravated tissue swelling preceded the appearance of angiosarcoma. Histogenetic classification of the tumor as hemangiosarcoma rather than lymphangiosarcoma was favored by positive immunohistochemical staining for Factor VIII. Despite high amputation and isolated perfusion with hyperthermal cytostatic infusion, she developed local recurrence and distant metastases and died 16 months after operation. Patients with chronic primary or secondary lymphedema are susceptible to angiosarcoma although the overall risk is small.