A rare blood vessel tumor that usually forms in the liver, lung, or bone, but it can also form on or in the skin. Epithelioid hemangioendotheliomas may be slow growing or fast growing and, in some people, may spread to other parts of the body very quickly. Signs and symptoms depend on where the tumor is in the body. On the skin, the tumor may be raised with round or flat, red-brown patches that feel warm. In the lung, the tumor can cause chest pain, trouble breathing, spitting up blood, and anemia. In the bone, the tumor can cause breaks. Epithelioid hemangioendotheliomas usually occur in adults, but can sometimes occur in children. They are a type of vascular tumor and a type of soft tissue sarcoma.