lymphocytosis
Quick Summary
Lymphocytosis is a condition characterized by an increase in the number of lymphocytes, a type of white blood cell crucial for the immune system. While normal variations in white blood cell counts occur, an elevated lymphocyte count can indicate underlying pathology.12
Lymphocytosis is often associated with viral infections, such as infectious mononucleosis caused by the Epstein-Barr virus. It can also be linked to certain chronic infections like tuberculosis and brucellosis. Additionally, lymphocytosis may be a sign of blood cancers, including chronic lymphocytic leukemia and multiple myeloma, or autoimmune disorders.12
The identification and counting of lymphocytes are part of a complete blood count (CBC) test, which aids in diagnosing and monitoring various medical conditions. Cancers arising from lymphocytes are known as leukemias, lymphomas, or myelomas, depending on where they are concentrated and the type of lymphocyte involved.23
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