Introduction to Leukaemia Flashcards
Define leukaemia
Malignancy characterised by unregulated clonal proliferation of one haematological cell type.
Clinical features of acute leukaemia
- > 20% immature blasts
- Prominent anaemia and thrombocytopenia
- WCC variable
- Mild lymphadenopathy and splenomegaly
Clinical features of chronic leukaemia
- Mild anaemia and thrombocytopenia
- Raised WCC
- Prominent lymphadenopathy and splenomegaly§
What factors influence prognosis?
- Age
- WCC at presentation
- Cytogenetics and karyotype
- Response to initial treatment
- MRD after tx
Why do we get BM failure in acute leukaemia?
Crowding out of normal cells by the leukaemic cells
What happens in leukostasis, and how does it present?
- Accumulation of blasts in the microcirculation and impaired perfusion
- Release cytokines and blast death products, which burden the kidneys
- Lungs: infiltrates and hypoxaemia
- CNS: fluctuating LOC, stroke
- Retinal haemorrhage: increased risk of ICH
- Priapism
What mutation is associated with AML in Trisomy 21?
GATA-1 mutations
Morphological features in APML?
- Biobed nuclei
- Faggott cell
- Hypergranularity
Blast morphology in ALL
- Large cells
- High nucleocytoplasmic ratio
- Thin rim of cytoplasm
- No granules
How do you differentiate between leukaemic infiltration of skin and petechiae caused by thrombocytopenia?
Leukaemic infiltration - raised papules on skin
Petechiae - not raised
What do you see in tumour lysis syndrome?
- Increased LDH and uric acid
- increased phosphate
- Hyperkalaemia
- Hypocalaemia
What are the principles of diagnosis?
- Morphology (light microscopy)
- Immunohistochemistry -although no longer done much
- Immunophenotyping
- Cytogenetics
- Molecular genetics
What are some established aetiological triggers in ALL?
- Ionising radiation
- Viruses e.g. EBV, HTLV-1
- Dyes - long exposure
- Cytotoxic drugs (Can cause a secondary leukaemia)
Cytochemistry in blasts
MPO and SBB indicate myeloblasts and we need >3% blasts to stain positive for these, to qualify as myeloblasts.
NSE - monocytic differentiation
Chloroactetate esterase: Bright red granular staining in promyelocytes onwards.
PAS: Positive in L1, L2; negative in l3
FITC in immunophentoyping
Fluoroscein Isothiocyanate
