In malignant tumors, the cells proliferate, grow rapidly and move to other parts of the body to form new tumors. This stage of disease is called

Options

A. metagenesis
B. metastasis
C. teratogenesis
D. mitosis

Answer

To solve the question regarding malignant tumors and their behavior, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Tumors**: Tumors are abnormal masses of tissue that can form when cells divide uncontrollably. They can be classified into two main types: benign and malignant.

2. **Defining Malignant Tumors**: Malignant tumors are cancerous and have the ability to invade nearby tissues and spread to other parts of the body. This is in contrast to benign tumors, which remain localized and do not spread.

3. **Cell Behavior in Malignant Tumors**: In malignant tumors, the cells lose the normal regulatory mechanisms that control cell division. They proliferate rapidly and can move to other locations in the body.

4. **Understanding the Process of Spread**: The process by which malignant tumor cells spread from their original site to form new tumors in other parts of the body is a critical characteristic of cancer. This involves the cells entering the bloodstream or lymphatic system.

5. **Identifying the Correct Term**: The specific term that describes the movement of malignant tumor cells to other parts of the body to form new tumors is known as "metastasis."

6. **Conclusion**: Therefore, the stage of disease where malignant tumor cells proliferate, grow rapidly, and move to other parts of the body to form new tumors is called **metastasis**.

### Final Answer:
The stage of disease in malignant tumors where cells proliferate, grow rapidly, and move to other parts of the body to form new tumors is called **metastasis**.

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