Malignancy refers to cells that are cancerous. Malignant cells may spread from their primary cancer source. This is called metastatic cancer.
Update Date 8/31/2014
Updated by: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.