Leukaemia (acute myeloblastic)

Question 1

Definition

Answer 1

· Malignancy of primitive myeloid lineage white blood cells (myeloblasts) with proliferation in the bone marrow and blood

o Classified using the FAB (French-American-British) System into EIGHT morphological variants

Question 2

Aetiology/risk factors

Answer 2

· Myeloblasts undergo malignant transformation and proliferation

· This leads to replacement of normal marrow and bone marrow failure

Question 3

Epidemiology

Answer 3

· MOST COMMON acute leukaemia in ADULTS

· Incidence INCREASES with age

Question 4

Presenting symptoms (bone marrow failure)

Answer 4

o Anaemia (lethargy, dyspnoea)
o Bleeding (due to thrombocytopaenia or DIC)
o Opportunistic or recurrent infections

Question 5

Presenting symptoms (tissue infiltration)

Answer 5

o Gum swelling or bleeding

o CNS involvement (headaches, nausea, diplopia)

Question 6

Signs on physical examination (bone marrow failure)

Answer 6

o Pallor
o Cardiac flow murmur
o Ecchymosis
o Bleeding
o Opportunistic or recurrent infections (e.g. fever, mouth ulcers, skin infections)

Question 7

Signs on physical examination (tissue infiltration)

Answer 7

o Skin rashes
o Gum hypertrophy
o Deposit of leukaemic blasts in the eye, tongue and bone (RARE)

Question 8

Investigations (blood)

Answer 8

· Bloods
o FBC - low Hb, low platelets, variable WCC
o High uric acid
o High LDH
o Clotting studies, fibrinogen and D-dimers (to check for DIC)

· Blood Film
o Myeloblasts

Question 9

Investigations (other)

Answer 9

· Bone Marrow Aspirate or Biopsy
o Hypercellular with > 20% blasts

· Immunophenotyping
o Antibodies against surface antigens used to classify the lineage of the abnormal clones

· Cytogenetics

· Immunocytochemistry