Post-mastectomy lymphangiosarcoma (Stewart-Treves syndrome): report of two long-term survivals.

Lymphangiosarcoma is one of the rarest forms of soft tissue neoplasms. Lowenstein (1906) was the first to report this entity in a patient with chronic post-traumatic upper extremity lymphoedema. However, it was not until Stewart and Treves (1948) described the development of this malignancy in a post-mastectomy oedematous extremity that this syndrome, which carries their name, became widely recognized. The tumour is highly malignant and usually arises in a lymphoedematous upper extremity of a patient treated for carcinoma of the breast. It has been well established that lymphangiosarcomas are not directly related to breast cancer (Aegerter & Peale, 1942). The common denominator is the lymphoedema and, therefore, other causes of chronic lymphoedema may lead to the development of this vascular sarcoma (Taswell et al, 1962). Indeed, this disease has occurred in congenital (Dubin et al,* 1974), idiopathic, traumatic and filarial lymphoedema (Devi & Bahuleyan, 1977). The pathogenesis of these unusual tumours remain uncertain. Stewart and Treves (1948) believed that a systemic carcinogen was involved in the etiology. Martorell (1951) suggested that the lymphoedema may be tumour inducing while Schreiber etal (1979) postulated that local immunodeficiency was the causative factor. Histologically these tumours consist of large vascular cavities lined with plump, spindle-shaped endothelial cells containing large nuclei and prominent nucleoli. Some areas may exhibit solid sheets of spindle cells (Silverberg et al, 1971). Immunohistochemistry may prove to be quite useful; factor VIII-AG is the most utilized marker for vascular differentitation (Mukai et al, 1980). Lymphangiosarcomas affect all races including blacks (DiSimone etal, 1970), orientals (Tomita etal, 1978) and Caucasians. The median time from mastectomy to the development of lymphangiosarcomas is 10 years (Woodward etal, 1972), ranging from 5 (Yap etal, 1981) to 27 years (Enzinger & Weiss, 1988). The average