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Get more information on the different types of acute lymphoblastic leukaemia (ALL).

There are two main types of acute leukaemia, myeloid and lymphoblastic. Lymphoblastic leukaemia can also be called lymphocytic leukaemia. ALL is divided into different groups (sub-types).

Doctors use two different systems to work out which type a person has. These are:

  • the French and British (FAB) system
  • the World Health Organisation (WHO) system

Ask your doctor which system they are using if you are unsure. The type of ALL you have tells you the type of cell that the cancer started in. Knowing this helps your doctor decide which treatment you need.

Finding the type of ALL

Your doctor looks at your leukaemia cells under a microscope to find out which group your leukaemia is in. 

Your doctor also does tests for:

  • proteins that some types of leukaemia cells make, these are called immunophenotyping tests
  • chromosome changes in the leukaemia cells, these are called cytogenetic tests

World Health Organisation (WHO) system

Doctors mostly use the World Health Organisation (WHO) system. It's based on the type of lymphocyte (white blood cell) that has become cancerous. This system helps your doctors to plan treatment and predict how well the treatment will work. There are three different subtypes:

  • pre (precursor) B cell ALL, this is the most common type in adults
  • mature B cell ALL, this type is identified by particular genetic changes
  • pre (precursor) T cell ALL, this is more likely to affect young adults and is more common in men

Mature B cell ALL is sometimes called Burkitt type ALL because it is similar to another cancer called Burkitt lymphoma.

French American British (FAB) system

This is an older system that doctors use less often. It divides ALL into 3 types:

  • L1 – the lymphocytes look quite like mature lymphocytes
  • L3 – the lymphocytes are very immature and look abnormal
  • L2 – this is somewhere in between and is the most common type in adults

Mixed type leukaemia

Some leukaemias seem to be a mixture of ALL and acute myeloid leukaemia (AML) . The abnormal cells have proteins (markers) from both types.

These are called acute biphenotypic leukaemias. Biphenotypic means both types. These kinds of leukaemia are rare.

Last reviewed: 
05 May 2015
  • Cancer and its management (6th edition)

    J Tobias and D Hochhauser

    Wiley Blackwell, 2010

  • How I treat mixed-phenotype acute leukemia
    O Wolach and R Stone
    Blood, 2015

    Volume 125

  • Wintrobe's Atlas of Clinical Hematology
    D Tkachuk and J Hirschmann 
    Lippincott, Williams and Wilkins, 2007

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