A purple plaque in a patient with systemic sclerosis.

We present the case of a 43-year old woman with anti-U3 ribonucleoprotein antibody-positive systemic sclerosis presenting with an enlarging purple plaque on the left upper arm. The skin was not sclerotic; however, there had been a cluster of long-standing telangiectases preceding the plaque. Histology and immunohistochemistry confirmed an angiosarcoma.