metastasize

verb4

1. •
   Of a disease (especially cancer) or a tumour: to form a metastasis (“a secondary focus away from the primary site”) in (a body organ).
2. •
   Of a disease (especially cancer) or a tumour: to undergo metastasis (“spreading from a primary site to one or more other sites in the body”).

   • Your lump could be a secondary cancer metastasized from the bowel. I had a patient like that not long ago. — 2001
3. •
   (figurative) To disseminate or spread (something, often an undesirable thing), especially in a destructive manner.
4. •
   (figurative) Of a thing, often one which is undesirable: to disseminate or spread, especially in a destructive manner.