A form of cancer caused by a type of herpesvirus that occurs mainly in the skin but may also occur in lymph nodes, internal organs and mucosal areas. The iatrogenic form tends to occur mainly on the lower legs but the internal organs are often involved as well. It generally affects immunosuppressed patients and can be aggressive or fairly benign. Symptoms depend on the extent of internal organ involvement. See also Kaposi sarcoma, iatrogenic form