Leukaemia - Chronic Myeloid Leukaemia

Question 1

Epidemiology

Answer 1

65-74 years old
Male
Radiation exposure

Question 2

Aetiology

Answer 2

Reciprocal chromosomal translocation between long arm of chromosome 9 and 22 = PHILEDELPHIA CHROMOSOME
BCR gene on chromosome 22 fuses with ABL gene from chromosome 9 = TYROSINE KINASE irreversibly switched ON = proliferation of myeloid cells

Question 3

Pathophysiology - 3 phases

Answer 3

Chronic phase = 5 years asymptomatic + diagnosed incidentally with raised WBC count
Accelerated phase = abnormal blast cell take up high proportion of cells in BM + blood (10-20%) = symptomatic
Blast phase/crisis = >20% = severe, often fatal

Question 4

Signs

Answer 4

MASSIVE HEPATOSPLENOMEGALY
Abdo tenderness
Signs of anaemia e.g pallor pyrexia

Question 5

Symptoms

Answer 5

Fatigue
Weight loss, Fever, Night sweats
SOB
Easy bruising and bleeding
Bone pain (BM expansion)

Question 6

Diagnosis

Answer 6

FBC: pancytopenia except granulocytosis
- Blood blast cell % =
<10% = chronic
10-19% = accelerated
>20% = blast crisis
GOLD STANDARD = cytogenetic testing - t(9:22) Philadelphia chromosome
Bone marrow biopsy = increased granulocytosis

Question 7

Treatment

Answer 7

FIRST LINE = IMATINIB
if CI give DASATINIB
+ chemo
+ allogeneic stem cell transplant
(consider allopurinol)

Question 8

Complications

Answer 8

Tumour lysis syndrome
Gout
Myelosuppression + neutropaenic sepsis