Lymphoblasts are immature cells that develop into lymphocytes, a type of white blood cell that is integral to the immune system. They are part of the body’s adaptive immune response, responsible for fighting infections and providing long-term immunity.

Where are lymphoblasts normally found?

Lymphoblasts are primarily found in the bone marrow, the soft, spongy center of bones where blood cells are produced. They originate from hematopoietic stem cells in the bone marrow and differentiate into various types of lymphocytes, including T cells, B cells, and natural killer (NK) cells.


What do lymphoblasts do?

The primary function of lymphoblasts is to mature into lymphocytes, which are crucial for the immune response. B lymphocytes produce antibodies to neutralize pathogens, T lymphocytes help regulate the immune responses and directly kill infected cells, and NK cells are involved in the rapid response to virally infected cells and tumor formation.

What medical conditions are associated with increased lymphoblasts?

An increase in lymphoblasts is typically associated with acute lymphoblastic leukemia (ALL), a type of cancer of the blood and bone marrow that affects white blood cells. ALL leads to the overproduction of immature white blood cells, crowding out normal cells and leading to various symptoms such as bleeding, infection, and anemia. Lymphoblasts can also be elevated in response to certain infections, especially viral infections, as the body ramps up its production of immune cells to fight the infection.

What do lymphoblasts look like under the microscope?

Under the microscope, lymphoblasts appear as larger cells with a high nucleus-to-cytoplasm ratio. They have a round or oval shape with fine chromatin in the nucleus and one or more prominent nucleoli. The cytoplasm is scant and basophilic, which means it stains blue with basic dyes due to its RNA content. In cases of leukemia, these cells can be seen in large numbers in blood smears and bone marrow samples.

About this article

Doctors wrote this article to help you read and understand your pathology report. Contact us if you have any questions about this article or your pathology report. Read this article for a more general introduction to the parts of a typical pathology report.

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