me·tas·ta·size 
(mĭ-tăstə-sīz′)
(mĭ-tăstə-sīz′)intr.v. me·tas·ta·sized, me·tas·ta·siz·ing, me·tas·ta·siz·es
1. To be transmitted or transferred by metastasis.
2. To be changed or transformed, especially dangerously: "a need for love that would metastasize into an insatiable craving for attention" (Michiko Kakutani).
3. To spread, especially destructively: "[disinformation] ... that even now continues to metastasize ... to such a degree that myth threatens to overthrow history" (Gore Vidal).