Benign WBC disorders

Question 1

leukemoid reaction

Answer 1

exaggerated response to infection defined as absolute leukocyte count > 50,000; caused by perforating appendicitis (neutrophils), whooping cough (lymphocytes), or nematodes (eosinophils)

Question 2

leukoerythroblastic reaction

Answer 2

immature bone marrow cells in PB; may be due to infiltrative disease (BM fibrosis, metastatic breast cancer) or severe BM stress (sepsis, growth factor)

Question 3

neutrophilia

Answer 3

absolute neutrophil count > 7,000; caused by infection, sterile inflammation with necrosis, or drugs

Question 4

neutropenia

Answer 4

absolute neutrophil count

Question 5

eosinophilia

Answer 5

absolute eosinophil count > 700; caused by type I hypersensitivity reaction, invasive helminths, hypocortisolism, or neoplasms (i.e. Hodgkin lymphoma)

Question 6

basophilia

Answer 6

absolute basophil count > 200; usually caused by CML, may also appear in CKD