Malignancy
The term "malignancy" refers to the presence of cancerous cells that have the ability to spread to other sites in the body (metastasize) or to invade nearby (locally) and destroy tissues. Malignant cells tend to have fast, uncontrolled growth and do not die normally due to changes in their genetic makeup.
Malignant cells that are resistant to treatment may return after all detectable traces of them have been removed or destroyed.

This abdominal CT scan shows tumor masses (malignant lymphomas) in the area behind the peritoneal cavity (retroperitoneal space).

Malignancy refers to cells that are cancerous. Malignant cells may spread from their primary cancer source. This is called metastatic cancer.
References
National Cancer Institute website. NCI dictionary of cancer terms.
Park BH. Cancer biology and genetics. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 171.
Version Info
Last reviewed on: 8/15/2022
Reviewed by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
