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.
The term malignant can be used in different ways, either to describe a cancerous tumor or a very serious medical condition. There are several similarities as well as differences between malignant and benign tumors. Learn about the characteristics and behavior of malignant tumors, the important ways in which they differ from benign tumors, and why it can sometimes be difficult to tell the difference between the two.Malignancy: A tumor that is malignant (cancerous), that can invade and destroy nearby tissue, and that may spread (metastasize) to other parts of the body.