Syndrome de Stewart Treves: une complication redoutable du lymphœdème

Stewart-treves syndrome (SST), also known as cutaneous angiosarcoma, is a rare and extremely serious complication of chronic lymphedema. Diagnosis is based on histology and immunohistochemistry. Treatment is primarily surgical. This syndrome occurs in 90% of cases after breast surgery. However, it can sometimes occur from other causes, as illustrated in our case study. The prognosis of Stewart-Treves syndrome is poor, with a five-year survival rate of approximately 10%, hence the importance of early diagnosis and prevention of lymphedema. We here report the case of a 70-year old female patient, with no history of breast cancer, axillary surgery or radiation therapy, presenting with left upper extremity swelling since 2010 complicated two years later by the appearance of a nodular lesion increasing progressively in size. Clinical examination showed a circumferential burgeoning polylobed tumor mass in the forearm associated with lymphoedema of the left upper extremity (Figure 1 A and Figure 1 B). The lymph nodes were free. The remaining elements in somatic examination were normal. The histology objectified tumor proliferation composed of a mixture of vascular cavities bounded by a layer of endothelium cells delimited by a basal membrane and surrounded by pericytes with immunohistochemical expression of CD31. Left upper extremity CT angiography showed a tumor mass in the left forearmss with vascular compression without bone involvement. After a multidisciplinary consultation left mid-arm amputation was performed, followed by radiation therapy. The patient didn’t develop recurrences; she underwent 27-month follow-up examination.