What type of tumor is characterized by its ability to spread into surrounding tissue?

A malignant tumor is characterized by its ability to invade and spread into surrounding tissues and organs. This invasive behavior is a key distinction from benign tumors, which remain localized and do not infiltrate adjacent tissues. Malignant tumors can also metastasize, meaning they can spread to distant sites in the body through the bloodstream or lymphatic system, forming secondary tumors.

In contrast, benign tumors typically grow in a controlled manner and do not exhibit aggressive behaviors, making them less dangerous. Static and localized are terms that do not accurately describe the invasive characteristics of tumors. Static would imply no growth or change, while localized suggests confinement to a specific area without invasion into surrounding tissues. Thus, the designation of a tumor as malignant is fundamentally connected to its capacity for invasion and metastasis.