Final answer:
Malignant tumors can spread through the blood to different parts of the body, a process known as metastasis. This is a common feature of malignant tumors and often leads to poor prognosis and increased mortality rates. Metastasis occurs when tumor cells enter the bloodstream and form new tumors in different tissues.
Step-by-step explanation:
Malignant tumors, also known as malignant neoplasms, can spread through the blood to other parts of the body. This is called metastasis, where tumor cells are shed and enter the bloodstream, allowing them to travel to different tissues. Once in a new location, these cells can form new tumors and continue to grow. Metastasis is a common feature of malignant tumors and is associated with the worst prognosis and most cancer deaths.