Stages of chronic lymphocytic leukaemia (CLL)

Staging for CLL helps doctors to know when you may need treatment, and which treatment would be best for your situation. Find out about the stages of CLL.

About stages of chronic lymphocytic leukaemia (CLL)

Doctors use staging to find out how much leukaemia there is in the body. This helps them know when you may need treatment and which treatment is best for your situation. There are 2 staging systems commonly used for chronic lymphocytic leukaemia (CLL) – the Binet system and the Rai system. The Binet system is most commonly used in the UK.

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Binet staging system

This looks at the number of white blood cells, red blood cells and platelets in the blood. It also looks at how many areas of lymph nodes are enlarged. These areas are in the neck, armpits, groin, liver and spleen. If the lymph nodes in both armpits are enlarged, it is only counted as one area. There are 3 stages in the Binet system:

  • Stage A – there are fewer than 3 areas of enlarged lymph nodes
  • Stage B – there are 3 or more areas of enlarged lymph nodes
  • Stage C – there are a reduced number of red blood cells, platelets or both.


In up to about 10% of people with CLL, the leukaemia can change. It can start to grow more quickly and become harder to treat. This is called transformation.

CLL may change into:

  • another type of leukaemia called prolymphocytic leukaemia
  • a type of lymphoma (cancer of the lymphatic system) called diffuse large B-cell lymphoma (DLBCL) – this transformation is called Richter’s syndrome
  • a type of lymphoma called Hodgkin lymphoma (but this is rare).

Transformation may cause:

  • a sudden swelling of affected lymph nodes, especially in the tummy (abdomen)
  • heavy sweats at night
  • weight loss
  • high temperatures (fever) with no obvious cause.

There may be other reasons for these symptoms. But always tell your doctor if you notice any of them.

Doctors can diagnose transformation of CLL with a bone marrow biopsy or a lymph node biopsy.

It is important to remember that transformation is unusual and does not happen for most people with CLL.

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Dr Helen Marr, Consultant Haematologist.

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