Leukemoid reaction

a moderate, advanced, or sometimes extreme degree of leukocytosis in the circulating blood, similar to that occurring in various forms of leukemia, but not the result of leukemic disease

Description
A leukemoid reaction usually encompasses a disproportionate increase in the number of forms (including immature stages) in one series of leukocytes. Various examples of myelocytic, lymphocytic, monocytic, or plasmocytic leukemoid reaction may be indistinguishable from leukocytosis that is associated with certain forms of leukemia. Leukemoid reactions are sometimes observed as a feature of
 * 1) infectious disease caused by certain bacteria and other biologic agents, e.g., tuberculosis, diphtheria, and chickenpox
 * 2) intoxication of various types, e.g., eclampsia, serious burns, and mustard gas poisoning
 * 3) malignant neoplasms, e.g., carcinoma of the colon, of the lung, of the kidney, or of other organs
 * 4) acute hemorrhage or hemolysis