A benign (not cancer) blood vessel tumor that is fully formed at birth. Congenital hemangiomas usually form on the skin of the head and neck or arms and legs. They may also form in organs, such as the liver. Congenital hemangiomas may be raised or flat and usually appear as purple-red lesions on the skin. Some congenital hemangiomas go away on their own; others only partly go away or do not go away at all. Congenital hemangiomas are a type of vascular tumor.