It typically arises in the soft tissues of the extremities (such as the hands, fingers, feet or lower legs) but can also develop elsewhere in the body.
It is characterised by the proliferation of cancerous cells that resemble epithelial cells — the cells that line the surfaces of organs and tissues. These cells can invade surrounding tissues and may spread to distant sites such as the lymph nodes or other organs. The exact cause is unknown and no specific risk factors have been identified.