What distinguishes a malignant tumor from a benign tumor?

A malignant tumor is distinguished from a benign tumor primarily by its potential to spread to other parts of the body, a characteristic known as metastasis. Malignant tumors have the ability to invade adjacent tissues and can also enter the bloodstream or lymphatic system, leading to the formation of secondary tumors in distant organs or tissues. This invasive behavior is a key factor in the increased risk and severity associated with malignant tumors.

In contrast, benign tumors typically do not spread and remain localized within their original site. While they can grow larger and may sometimes exert pressure on surrounding structures, they do so without the aggressive invasion and metabolic changes seen in malignant tumors. Understanding this fundamental difference is crucial for assessing the prognosis and treatment options for patients with tumors.