DDx granulocytosis and CML

Question 1

Granulocytosis

Answer 1

Increased number of granulocytes in the peripheral blood

Question 2

Causes of granulocytosis

Answer 2

Infection/leukemoid reaction: CML
Neutrophilia: bacterial infection, CML, myeloproliferative disorder
Eosinophilia: parasites, allergy, vasculitis (Churg-Strauss)
Basophilia: CML, allergies/inflammatory condition

Question 3

Leukemoid reaction

Answer 3

WBC > 50 G/L - inflammatory response
May appear like leukemia, e.g. CML
Key differences from CML
- Leukemoid reaction has toxic granulations and increased inflammatory markers
- Does not have basophilia or BCR-ABL fusion gene
LAP score

Question 4

LAP score

Answer 4

The leukocyte alkaine phosphatase (LAP) score is often used in patients with an elevated WBC to differentiate a reactive process from chronic myelogenous leukemia

Question 5

CML (15% of leukemias)

Answer 5

Uncontrolled clonal proliferation of myeloid cells

Question 6

Etiology of CML

Answer 6

Philadelphia chromosome > 80% of patients

Ch 9, Ch 22 -> t(9;22) -> BCR/ABL = tyrosine kinase activity = uncontrolled clonal proliferation

Question 7

CML symptoms

Answer 7

Weight loss, tiredness/fatigue, night sweats, hepatosplenomegaly, anemia, bruising(thrombocytopenia)
Can be asymptomatic

Question 8

Dx

Answer 8

Complete blood count, 
increased WBC with whole myeloid spectrum, 
decreased Hb, 
cytogenetics of Ph chromosome 
Leukocytosis, small number of blasts 
Decreased LAP 
BONE MARROW BIOPSY
Thrombocytosis

Question 9

Tx

Answer 9

Imatinib = BCR - ABL tyrosine kinase inhibitor
Dasatinib
Hydroxycarbamide
Stem cell transplantation - allogeneic: HLA match - the only cure - significant morbidity and mortality

Question 10

CML compared to AML

Answer 10

CML lower number of blasts