What characterizes metastatic tumors?

Metastatic tumors are characterized by their ability to travel from one part of the body to another, specifically from a primary tumor site to distant organs or tissues. This process, known as metastasis, occurs through various routes, including the bloodstream or lymphatic system. When cancer cells detach from the original tumor, they can spread and form new tumors in different areas, often leading to complications and more advanced stages of disease.

In contrast, tumors that originate from the brain itself are classified as primary brain tumors, and these do not meet the definition of metastatic tumors. Furthermore, while metastatic tumors can sometimes manifest as secondary tumors in the brain, they are not considered the most common type of primary tumor, which would be primary tumors from various organs. Lastly, metastatic tumors typically exhibit aggressive behavior rather than benign characteristics, as they tend to invade surrounding tissues and can lead to significant health issues.