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.

What is staging for chronic lymphocytic leukaemia (CLL)?

Doctors use staging to find out how much leukaemia there is in the body. This helps them know how advanced the chronic lymphocytic leukaemia (also called CLL or CLL leukemia) is. There are 2 staging systems commonly used for CLL:

  • the Binet system
  • the Rai system.
The Binet system is most commonly used in the UK.


We understand that waiting to know the stage of your cancer can be a worrying time. We're here if you need someone to talk to. You can:

Binet staging system

The Binet staging system 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.

Chronic lymphocytic leukaemia (CLL) transformation

In up to about 10% of people with CLL (1 in 10), 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, a lymph node biopsy and blood tests.

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

About our information

  • References

    Below is a sample of the sources used in our chronic lymphocytic leukaemia (CLL) information. If you would like more information about the sources we use, please contact us at

    Schuh A et al. Guideline for the treatment of chronic lymphocytic leukaemia. British Society for Haematology Guidelines. July 2018.

    Eichhorst B et al. Chronic lymphocytic leukaemia: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. ESMO Guidelines Committee. October 2020.

  • 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 Anne Parker, Consultant Haematologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

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Date reviewed

Reviewed: 01 February 2022
Next review: 01 February 2025
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.