Leukaemia
Summary
Leukaemia is malignancy of haematopoietic cells characterised by abnormal proliferation of white blood cells. It is classified by cell lineage (lymphoid or myeloid) and tempo (acute or chronic). Acute leukaemias (ALL, AML) present with bone marrow failure (anaemia, thrombocytopenia, neutropenia) and require urgent treatment. Chronic leukaemias (CLL, CML) often have an indolent course. Treatment depends on subtype and may include chemotherapy, targeted therapy, or stem cell transplantation.
Key Facts
- Classification: Acute (ALL, AML) vs Chronic (CLL, CML); Lymphoid vs Myeloid
- Most Common in Adults: CLL (chronic), AML (acute)
- Most Common in Children: ALL
- Presentation: Fatigue, infection, bleeding, hepatosplenomegaly
- Diagnosis: Blood film + bone marrow biopsy
- Philadelphia Chromosome: t(9;22) — defines CML, present in some ALL
Clinical Pearls
"Blast Crisis is the Danger": In CML, transformation to blast crisis has very poor prognosis.
"Auer Rods = AML": Auer rods in blasts are pathognomonic for AML.
"Philadelphia Positive = TKI": CML is treated with tyrosine kinase inhibitors (imatinib).
"Watch and Wait": Many CLL patients never need treatment.
Why This Matters Clinically
Leukaemia requires urgent recognition. Acute leukaemias are medical emergencies. Targeted therapies have transformed outcomes in CML and some CLL. Neutropenic sepsis is a common, life-threatening complication.
Incidence
| Type | Age | Notes |
|---|---|---|
| ALL | Peak 2-5 years | Most common childhood cancer |
| AML | Peak >5 years | Most common acute leukaemia in adults |
| CLL | Median 70 years | Most common leukaemia overall |
| CML | Median 55 years | 15-20% of adult leukaemias |
Mechanism
- Clonal expansion of abnormal haematopoietic cells
- Bone marrow replacement → cytopenias
- Infiltration of organs (liver, spleen, CNS)
- Genetic mutations drive proliferation
Key Genetic Abnormalities
| Abnormality | Leukaemia | Significance |
|---|---|---|
| t(9;22) BCR-ABL1 | CML, Ph+ ALL | TKI therapy |
| t(15;17) PML-RARA | APL | ATRA + ATO |
| t(8;21) | AML | Favourable prognosis |
| FLT3-ITD | AML | Adverse; FLT3 inhibitors |
| del(17p)/TP53 | CLL | Poor prognosis |
Symptoms
Signs
| Sign | Notes |
|---|---|
| Pallor | Anaemia |
| Petechiae/purpura | Thrombocytopenia |
| Hepatosplenomegaly | Extramedullary haematopoiesis |
| Lymphadenopathy | ALL, CLL |
| Gum hypertrophy | Monocytic AML |
Red Flags
[!CAUTION] Emergencies:
- Neutropenic sepsis
- Tumour lysis syndrome
- DIC (especially APL)
- Hyperleukocytosis (leukostasis)
- Spinal cord compression
- Pallor, bruising, petechiae
- Lymphadenopathy
- Hepatosplenomegaly
- Gum hypertrophy
- Signs of infection
| Test | Purpose |
|---|---|
| FBC | WCC, Hb, Platelets |
| Blood Film | Blasts, smudge cells (CLL) |
| Bone Marrow Biopsy | Definitive diagnosis |
| Immunophenotyping | Lineage determination |
| Cytogenetics | Prognostic, therapeutic |
| Molecular | FLT3, NPM1, BCR-ABL1 |
Acute Leukaemias
| Type | Treatment |
|---|---|
| ALL | Multi-agent chemo, CNS prophylaxis, ± transplant |
| AML | 7+3 induction, consolidation, ± transplant |
| APL | ATRA + Arsenic trioxide |
Chronic Leukaemias
| Type | Treatment |
|---|---|
| CML | TKI (imatinib first-line) |
| CLL | Watch and wait, BTK/BCL-2 inhibitors when indicated |
| Complication | Notes |
|---|---|
| Neutropenic Sepsis | Medical emergency |
| Tumour Lysis Syndrome | Metabolic emergency |
| DIC | Especially APL |
| Relapse | Major cause of mortality |
| Type | Prognosis |
|---|---|
| ALL (children) | 90% cure rate |
| ALL (adults) | 40-50% cure |
| AML | 40% 5-year survival |
| APL | 85% cure with ATRA/ATO |
| CML | Near-normal life expectancy with TKI |
| CLL | Variable; many never need treatment |
Key Guidelines
- NICE: Haematological cancers
- BSH Guidelines: AML, ALL, CLL, CML
What is Leukaemia?
Leukaemia is cancer of the blood cells. It starts in the bone marrow where blood cells are made.
Types
- Acute: Develops quickly, needs urgent treatment
- Chronic: Develops slowly, may not need immediate treatment
Symptoms
- Tiredness
- Frequent infections
- Easy bruising or bleeding
- Swollen glands
Treatment
- Chemotherapy
- Targeted drugs
- Sometimes bone marrow transplant
-
National Institute for Health and Care Excellence. Haematological cancers. nice.org.uk
-
British Society for Haematology. Guidelines for AML, ALL, CLL, CML. b-s-h.org.uk
Medical Disclaimer: MedVellum content is for educational purposes. Leukaemia requires specialist haematology care.