Mitosis is the process that cells use to divide and create new cells. Your body constantly relies on mitosis to replace old, damaged, or worn-out cells with fresh, healthy ones. Before a cell divides, it prepares by duplicating its genetic material (DNA) so that each new cell receives an exact copy. Cells undergoing mitosis are called mitotic figures, and pathologists can see these cells when examining tissue samples under a microscope.
What are the stages of mitosis?
Mitosis occurs in four main stages, each with distinct features:
-
Prophase: The cell prepares for division by duplicating its genetic material (DNA), ensuring enough DNA supply for two new cells.
-
Metaphase: The duplicated genetic material aligns in the center of the cell, making it ready for separation.
-
Anaphase: The cell begins splitting into two separate cells, pulling the duplicated genetic material apart so that each new cell has a complete set of DNA.
-
Telophase: Two separate new cells are fully formed, each with its own complete set of genetic material enclosed within its nucleus.
Is it normal to see mitosis in a tissue sample?
Yes, it is entirely normal to see mitotic figures in many healthy tissues because your body constantly replaces old or damaged cells. Rapidly renewing tissues such as skin, intestines, and bone marrow frequently show mitotic figures under the microscope. However, an unusually high number of mitotic figures can indicate abnormal conditions, including infections, inflammation, or cancer.
Why do pathologists look for mitosis?
Pathologists look for mitotic figures because counting the number of dividing cells in a tissue sample provides valuable information about how rapidly the cells are growing. In cancers, many mitotic figures suggest that the tumor cells are dividing quickly and could indicate a more aggressive disease. This helps your medical team determine the cancer grade and select appropriate treatment options. Additionally, tumors with many dividing cells are often more responsive to treatments like chemotherapy, which specifically targets rapidly dividing cells.
