WBC Disorders

leukemoid reaction

• reactive leukocytosis above 50 ×10³/uL with neutrophilia and a marked left shift

  • mostly bands and metas/myelos

• caused by

  • severe and/or chronic infection

  • metabolic disease

  • inflammation

  • response to a malignancy

leukoerythroblastic picture

• presence of immature neutrophils, nRBCs, and teardrop RBCs in same sample

• strongly associated with primary myelofibrosis

False

True or false: LAP is increased in CML

Philadelphia chromosome

t(9;22)

JAK2 mutation

mutation which is common to polycythemia vera, essential thrombocythemia, and primary myelofibrosis, but is most significant with PV

imatinib

tyrosine kinase inhibitor used to treat CML

polycythemia vera (PV)

disorder which has the following WHO criteria for diagnosis:

1. Elevated Hb and HCT

2. BM hypercellularity with trilineage growth (panmyelosis)

3. Identification of JAK2 mutation

leukemoid reaction

LAP score is high in _______

essential thrombocythemia (ET)

characterized by marked and persistent thrombocytosis

• platelets range from 600-2,000 × 10⁹/L (>450)

• large masses of platelet aggregates

• abnormal platelet morphology

  • giant and bizarre forms

  • megakaryocyte forms

• PLT function studies and aggregation are abnormal

• PLT function goes back to normal when PLT count goes down to normal

primary myelofibrosis (PMF)

• abnormal clone of megakaryocytes stimulate the BM fibroblasts to produce collagen

• fibrosis → dry tap during BM biopsy

• leads to progressive bone marrow failure

• results in extramedullary hematopoiesis

primary myelofibrosis (PMF)

Peripheral blood film:

• immature granulocytes

• nRBCs

• teardrops

• giant platelets and other bizarre RBC shapes

• micromegakaryocytes

t(8;21) (RUNX1/RUNX1T1)