An "anaplastic" Kaposi's sarcoma mimicking a Stewart-Treves syndrome. A case report and a review of literature

Cutaneous angiosarcoma (AGS) developing in a lymphedematous arm, after lymphadenectomy in the context of breast cancer, is the definition of the classical Stewart-Treves syndrome. Like AGS, many tumors such as Kaposi's sarcoma (KS) could develop in chronic lymphedema. We describe the case of a 50-year-old woman who presented with several nodules on the left lymphedematous arm evocative of a Stewart-Treves syndrome, 2 years after a left mastectomy and a homolateral lymphadenectomy. The histological examination revealed an atypical vascular proliferation suggesting AGS, but endothelial atypical cells nuclei were strongly stained by herpes human virus 8 antibody. The final diagnosis was an "anaplastic" KS mimicking a Stewart-Treves syndrome. The total regression of the lesion was obtained by elastic contention and intradermic liposomal doxorubicin. "Anaplastic" KS is a rare histological form of nodular KS, which mimics a cutaneous AGS but classically expresses herpes human virus 8. It is essential to know about this entity, particularly in a lymphedematous arm, to avoid aggressive treatment such as amputation.