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 answer the question regarding the stage of disease in malignant tumors where cells proliferate, grow rapidly, and move to other parts of the body to form new tumors, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Malignant Tumors**:
- Malignant tumors are characterized by uncontrolled cell growth and the ability to invade surrounding tissues. They can spread to other parts of the body.

2. **Identifying the Process of Spread**:
- The process by which cancer cells spread from the original (primary) site to other parts of the body is critical to understanding the progression of malignant tumors.

3. **Terminology**:
- The term "metastasis" refers specifically to the spread of cancer cells from the primary tumor to distant sites in the body, where they can form new tumors.

4. **Conclusion**:
- Therefore, the stage of disease where malignant tumor cells proliferate, grow rapidly, and migrate to form new tumors in other parts of the body 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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