Chronic Myeloid Leukaemia

Question 1

Definition of chronic myeloid leukaemia

Answer 1

Is malignant clonal disorder of the haematopoietic stem cell that results in marked myeloid hyperplasia of the bone marrow

Question 2

Aetiology of chronic myeloid leukaemia

Answer 2

• Increased risk with exposure to ionising radiation
• Occurs most often between 40-60 years old
• More common in MALES

Question 3

Pathophysiology of chronic myeloid leukaemia

Answer 3

• Malignant proliferation of stem cells
◦ In most cases is usually due to the presence of the PHILADELPHIA CHROMOSOME (present in >80% of CML patients)
◦ Would result in the formation of a fusion gene (BCR-ABL on chromosome 22)
◦ This gene has excessive tyrosine kinase activity
◦ Would transform normal stem cells into malignant ones

• Has 3 stages:
• Chronic: few symptoms
• Accelerated phase: increasing symptoms
• Blast transformation: feature of acute leukaemia

Question 4

History and Examination of chronic myeloid leukaemia

Answer 4

• Chronic and insidious
• Weight loss: likely in accelerated phase
• Excessive sweating: likely in accelerated phase
• Splenomegaly: very common

• Tiredness, pallor, SOB: anaemia
• LUQ discomfort or early satiety: due to splenomegaly
• Bleeding, epistaxis, bruising: thrombocytopenia
• Infection
• Gout/Arthralgia: due to purine breakdown

Question 5

Investigations of chronic myeloid leukaemia

Answer 5

• FBC:
‣ majority have very raised WCC, with whole spectrum of myeloid cells increased (increased neutrophils, monocytes, basophils etc)
‣ Hb would be low, anaemia
‣ Thrombocytopenia
• Blood film: large number of mature/maturing myeloid cells
• Bone marrow biopsy: granulocytic hyperplasia
• Cytogenetic studies: can show the Philadelphia chromosome

Question 6

Treatment of chronic myeloid leukaemia

Answer 6

1) Tyrosine Kinase Inhibitor (IMATINIB): IMATINIB is well tolerated and has mild side effects (nausea, cramps, oedema etc). Increases survival

Question 7

Complications and prognosis of chronic myeloid leukaemia

Answer 7

• Pancytopenia: complication of blast crisis, can have RBC/platelet transfusions if needed)

Taking a tyrosine kinase inhibitor (e.g imatinib) can greatly increase survival