Mitotic figure

A mitotic figure is a cell that is actively dividing to create two new cells. Cells divide through a process called mitosis, creating two new cells from one original cell. Before dividing, a cell copies its genetic material (DNA), ensuring that each new cell receives identical instructions. Pathologists recognize mitotic figures by their unique appearance, which indicates a cell is in the middle of dividing.

Are mitotic figures normal?

Mitotic figures are normal and can be seen regularly in many healthy tissues. Cells naturally divide to help the body grow, heal, and replace old or damaged cells. Tissues that regularly renew themselves, such as your skin, the lining of your intestines, and bone marrow, typically have numerous mitotic figures. However, seeing many mitotic figures might signal an abnormal condition or rapid cell growth.

Why do pathologists look for mitotic figures?

Pathologists look carefully for mitotic figures because the number they see gives important clues about how fast cells in a tissue sample are growing and dividing. In cancer, many mitotic figures can indicate that the tumor cells are dividing rapidly, which often means the cancer could behave aggressively. Counting mitotic figures helps pathologists determine the grade (how aggressive it is) of certain cancers, assisting your doctor in deciding on the most effective treatment.

What does a mitotic figure look like?

Under a microscope, mitotic figures stand out because they appear distinct from non-dividing cells. Their genetic material (DNA), normally evenly distributed inside a cell’s nucleus, appears condensed and arranged into specific patterns or shapes. Depending on which stage of mitosis the cell is in, mitotic figures might look like tightly bundled threads, lines in the center of the cell, or two separate clusters pulling apart from each other.

What does it mean if a cancer has lots of mitotic figures?

If a cancer has many mitotic figures, it typically means the tumor is growing and dividing rapidly. This finding is important because cancers with higher numbers of mitotic figures are often more aggressive, meaning they may grow faster and spread more easily to other areas. However, cancers with numerous mitotic figures may also respond better to treatments such as chemotherapy, which targets actively dividing cells. Your doctor will consider this information to determine the best possible approach to your treatment.