Leukaemia is the name for cancer of a particular line of the stem cells in the bone marrow. This causes unregulated production of certain types of blood cells. Types of leukaemia can be classified depending on how rapidly they progress (chronic is slow and acute is fast) and the cell line that is affected (myeloid or lymphoid).


Types of Leukaemia

The types of leukaemia that affect children from most to least common are:

  • Acute lymphoblastic leukaemia (ALL) is the most common in children
  • Acute myeloid leukaemia (AML) is the next most common
  • Chronic myeloid leukaemia (CML) is rare

Rarer and very specialist leukemias exist, but you are very unlikely to encounter them.



  • ALL peaks aged 2 – 3 years
  • AML peaks aged under 2 years



Leukaemia is a form of cancer of the cells in the bone marrow. A genetic mutation in one of the precursor cells in the bone marrow leads to excessive production of a single type of abnormal white blood cell.

The excessive production of a single type of cell can lead to suppression of the other cell lines, causing underproduction of other cell types. This results in a pancytopenia, which is a combination of low:

  • Red blood cells (anaemia),
  • White blood cells (leukopenia)
  • Platelets (thrombocytopenia)


Risk Factors

Radiation exposure, for example with an abdominal xray during pregnancy, is the main environmental risk factor for leukaemia.

There are several conditions that predispose to a higher risk of developing leukaemia:

  • Down’s syndrome
  • Kleinfelter syndrome
  • Noonan syndrome
  • Fanconi’s anaemia



The presentation of leukaemia is typically non-specific. Symptoms can include:

  • Persistent fatigue
  • Unexplained fever
  • Failure to thrive
  • Weight loss
  • Night sweats
  • Pallor (anaemia)
  • Petechiae and abnormal bruising (thrombocytopenia)
  • Unexplained bleeding (thrombocytopenia)
  • Abdominal pain
  • Generalised lymphadenopathy
  • Unexplained or persistent bone or joint pain
  • Hepatosplenomegaly



NICE recommend referring any child with unexplained petechiae or hepatomegaly for immediate specialist assessment.

If leukaemia is suspected based on the non-specific signs above, NICE recommend a very urgent full blood count within 48 hours.

Investigations to establish the diagnosis:

  • Full blood count, which can show anaemia, leukopenia, thrombocytopenia and high numbers of the abnormal WBCs
  • Blood film, which can show blast cells
  • Bone marrow biopsy
  • Lymph node biopsy


Further tests may be required for staging:

  • Chest xray
  • CT scan
  • Lumbar puncture
  • Genetic analysis and immunophenotyping of the abnormal cells



Treatment of leukaemia will be coordinated by a paediatric oncology multi-disciplinary team. Leukaemia is primarily treated with chemotherapy.

Other therapies:

  • Radiotherapy
  • Bone marrow transplant
  • Surgery


Complications of Chemotherapy

  • Failure to treat the leukaemia
  • Stunted growth and development
  • Immunodeficiency and infections
  • Neurotoxicity
  • Infertility
  • Secondary malignancy
  • Cardiotoxicity



The overall cure rate for ALL is around 80%, but prognosis depends on individual factors. The outcomes are less positive for AML.


Last updated January 2020