noun, plural: lymphocytoses
A condition in which there is an abnormally high level of lymphocytes in the blood.
Lymphocytosis is a type of leukocytosis in which the increased white blood cell count involves the lymphocytes.
Lymphocytosis is not a disease but a laboratory finding indicating possible infection or inflammation. This condition causes no symptoms, and usually an individual may find out by chance to have lymphocytosis through routine blood tests. This condition is commonly associated with acute lymphoblastic leukemia, sunburn, pertussis, toxoplasmosis, and some viral infections such as mumps, Epstein-Barr virus infection, hepatitis, rubella, etc.
Word origin: lymphocyte + Latin –osis, from Greek –osis (an increase, a condition).
Related forms: lymphocytotic (adjective).
See also: leukocytosis.