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Chronic lymphocytic leukemia (CLL)



Chronic lymphocytic leukemia is cancer of a type of white blood cells called lymphocytes.

See also:

Alternative Names

CLL; Leukemia - chronic lymphocytic (CLL)


Chronic lymphocytic leukemia (CLL) causes a slow increase in the number of white blood cells called B lymphocytes, or B cells, in the bone marrow. The cancerous cells spread from the blood marrow to the blood, and can also affect the lymph nodes or other organs such as the liver and spleen. CLL eventually causes the bone marrow to fail, resulting in low blood counts, and weakens the immune system.

The reason for this increase in B cells is unknown. There is no link to radiation, cancer-causing chemicals, or viruses.

CLL primarily affects adults. The average age of patients with this type of leukemia is 70. It is rarely seen in people younger than 40. The disease is more common in Jewish people of Russian or East European descent, and is uncommon in Asians.


Symptoms usually develop slowly over time. Many cases of CLL are detected by blood tests done in people for other reasons or who do not have any symptoms.

Symptoms that can occur include:

Signs and tests

Patients with CLL usually have a higher-than-normal white blood cell count.

Tests to diagnose and assess CLL include:

  • Complete blood count (CBC) with white blood cell differential
  • Bone marrow aspiration and biopsy
  • CT scan of the chest, abdomen, and pelvis
  • Flow cytometry usually done on blood or bone marrow
  • Blood immunoglobulin level
  • Blood lactate dehydrogenase level

If your doctor discovers you have CLL, tests will be done to see how much the cancer has spread. This is called staging.

There are two systems used to stage CLL:

  • The Rai system uses numbers to group CLL into low-, intermediate-, and high-risk categories. Generally, the higher the stage number, the more advanced the cancer.
  • The Binet system uses letters to stage CLL according to how many lymph node groups are involved and whether you have a drop in the number of red blood cells or platelets.

Some newer tests analyze the chromosomes in the leukemia cells.The results can help predict prognosis and help guide how strong or aggressive the treatment needs to be.

Expectations (prognosis)

The outlook depends on the stage and behavior of the disease. Half of patients diagnosed in the earliest stages of the disease live more than 12 years. Some people may not require any treatment at all, while others may have faster spreading disease that requires aggressive therapy with multiple chemotherapy agents.

Newer tests that look at cell genetic changes may be done to help predict disease behavior and thus guide treatment approaches.

Calling your health care provider

Call health care provider if you develop enlarged lymph nodes or unexplained fatigue, bruising, excessive sweating, or weight loss.

  • Autoimmune hemolytic anemia
  • Bleeding from low platelet count
  • Fatigue from anemia
  • Hypogammaglobulinemia (reduced levels of antibodies) -- increases the risk of infection
  • Idiopathic thrombocytopenic purpura (ITP)
  • Recurrent infections
  • Other cancers, including transformation to a much more aggressive lymphoma (Richter’s transformation)
  • Side effects of chemotherapy

For most patients with early stage CLL, no treatment is started. However, these people must be closely watched by their doctor.

If chromosome tests indicate a more high risk type of leukemia, treatment may be started earlier.

Treatment may also be started if:

  • Infections keep coming back
  • Leukemia is growing rapidly.
  • Low blood counts (anemia and thrombocytopenia (low platelet count) are present
  • Fatigue, loss of appetite, weight loss, or night sweats occur

Several chemotherapy drugs are commonly used to treat CLL.

  • Fludarabine, chlorambucil, cyclophosphamide (Cytoxan), and rituximab (Rituxan) may be used alone or in combination.
  • Alemtuzumab (Campath) is approved for treatment of patients with CLL that have not responded to fludarabine.
  • Bendamustine is a newer drug recently approved for use in patients with CLL that has come back after initial treatment.

Rarely, radiation may be used for painfully enlarged lymph nodes. Blood transfusions or platelet transfusions may be required if blood counts are low.

Bone marrow or stem cell transplantation may be used in younger patients with advanced CLL. Right now, transplant is the only therapy that offers a potential cure for CLL.



Kantarjian H, O'Brien S. The chronic leukemias. In: Goldman L, Ausiello D, eds. Cecil Textbook of Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 195.

Grever M, Andritsos LA, Lozanski G. Chronic lymphoid leukemia. In: Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKenna WG, eds. Abeloff’s Clinical Oncology. 4th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 108.

Related Taxonomy

Review Date: 3/2/2010
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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