Difficult diagnosis: The Stewart-Treves syndrome vs. Kaposi sarcoma following mastectomy for breast cancer - A case report

Abstract

The Stewart-Treves syndrome is defined as lymphangiosarcoma of an extremity appearing due to chronic lymphedema, classically following radical mastectomy for breast cancer. We report the case of a 67 years old women admitted for an angiosarcoma of the right forearm occurring 14 years after a modified radical mastectomy and adjuvant chemotherapy for carcinoma of the right breast. A wide excision of the lesion and split-thickness skin graft was performed with uneventful recovery and satisfactory healing of the graft tissue and functional aspect of the arm. The pathological examination showed conventional high-grade angiosarcoma with a mixture of vasoformative features, whereas the immunohistochemical tests showed Ki67 positive expression in 70% of tumor, CD31 and CD34 intense positive, Factor 8 positive and HHV8 intense diffuse at nuclear level which advocates for nodular Kaposi sarcoma. Further on, the D2-40 and Flt-4 (VEGF-R3) detection were positive on lymphatic endothelium. Lymphangiosarcoma is a rare and aggressive tumor with a very poor prognosis. Early clinical diagnosis and histological confirmation may pose extreme difficulties. Moreover, the clinician should be aware of this rare pathological entity and regard it in the diagnosis algorithm of the patients with nodules linked to chronic lymphedema. It is worth mentioning that in our experience of more than 1100 cases of breast cancer – diagnosed, operated and followed by the same surgical team in the last 10 years, this is the first Stewart- Treves syndrome versus Kaposi sarcoma case we encountered.