B cells

MyPathologyReport
October 1, 2023

B cells (also called B lymphocytes) are a type of white blood cell and a part of the immune system. These cells contribute to a process called the adaptive immune response that is important for protecting the body against infections. Specifically, these cells contribute to humoral immunity by producing immunoglobulin (antibodies) that recognize and stick to chemicals that are not normally produced in the body – such as those made by viruses. A plasma cell is a type of B cell that has been activated in the past and is capable of producing one type of immunoglobulin.

These cells come from hematopoietic stem cells found in the bone marrow. These cells are called stem cells because they give rise to all the cells in the blood and immune system. Once mature, these cells travel to lymphoid organs such as lymph nodes which are found throughout the body. Large numbers of these cells can also be found in an area of inflammation caused by infection or injury.

What markers are used to identify B cells?

Common markers used to identify B cells include CD20 and CD79a. Pathologists perform tests such as immunohistochemistry and flow cytometry to see cells making CD20 and CD79a.

What types of cancer are made up of B cells?

Most cancers made up of B cells are part of a group of cancers called lymphoma and the most common types are small lymphocytic lymphoma, follicular lymphoma, diffuse large B cell lymphoma, mantle cell lymphoma, and extranodal marginal zone lymphoma.

About this article

Doctors wrote this article to help you read and understand your pathology report. Contact us with 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.

Other helpful resources

Atlas of Pathology