Overview

Chronic lymphocytic leukemia (CLL) is a type of leukemia. Leukemia is cancer that affects the blood and bone marrow. Bone marrow is the spongy tissue inside bones where blood cells are made.

The term "chronic" in chronic lymphocytic leukemia refers to the slower progression of this cancer. CLL typically progresses more slowly than other types of leukemia. The term "lymphocytic" refers to the cells affected by the disease. The cells are a group of white blood cells called lymphocytes. Lymphocytes help your body fight infection.

Treatments for chronic lymphocytic leukemia may include a "watch and wait" approach, targeted therapy, chemotherapy, immunotherapy and bone marrow transplant, also known as bone marrow stem cell transplant. Other treatment options may include CAR-T cell therapy, radiation therapy and clinical trials.

Symptoms

Chronic lymphocytic leukemia symptoms may not happen right away. Symptoms may develop as the cancer progresses. When symptoms happen, they may include:

  • Swollen lymph nodes, which might feel like a lump under the skin. They happen most often in the neck, armpit and groin.
  • Fever.
  • Drenching night sweats.
  • Fatigue.
  • Weight loss without trying.
  • Loss of appetite.
  • Pain in the upper left part of the belly, which may be caused by an enlarged spleen.
  • Frequent infections.

When to see a doctor

Make an appointment with a healthcare professional if you have any symptoms that worry you.

Causes

It's not clear what causes chronic lymphocytic leukemia. Cancer happens when cells develop changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA gives instructions to grow and multiply at a set rate. The instructions tell the cells to die at a set time. In cancer cells, the DNA changes give different instructions. The changes tell the cancer cells to make many more cells quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells. In chronic lymphocytic leukemia, the cancer cells can build up in the blood, bone marrow, lymph nodes and other parts of the body.

Risk factors

Factors that may increase the risk of chronic lymphocytic leukemia include:

  • Your age. Chronic lymphocytic leukemia happens most often in adults older than 55.
  • Your race. White people are more likely to develop chronic lymphocytic leukemia than are people of other races.
  • Family history of blood and bone marrow cancers. A family history of chronic lymphocytic leukemia or other blood and bone marrow cancers may increase your risk.
  • Exposure to chemicals. Certain herbicides and insecticides, including Agent Orange used during the Vietnam War, have been linked to an increased risk of chronic lymphocytic leukemia.
  • A condition that causes excess lymphocytes. Monoclonal B-cell lymphocytosis (MBL) causes an increased number of a type of lymphocyte, called B lymphocytes, in the blood. For a small number of people with MBL, the condition may develop into chronic lymphocytic leukemia. If you have MBL and also have a family history of chronic lymphocytic leukemia, you may have a higher risk of developing cancer.

Complications

Chronic lymphocytic leukemia may cause complications such as:

  • Frequent infections. If you have chronic lymphocytic leukemia, you may get infections more often. These infections can be serious. Sometimes infections happen because your blood doesn't have enough germ-fighting antibodies, called immunoglobulins. Your healthcare professional might recommend regular immunoglobulin infusions.
  • A switch to a more aggressive form of cancer. A small number of people with chronic lymphocytic leukemia may develop a more aggressive form of cancer called diffuse large B-cell lymphoma. This is sometimes referred to as Richter syndrome.
  • Increased risk of other cancers. People with chronic lymphocytic leukemia have an increased risk of other types of cancer. These include skin cancer and cancers of the lung and the digestive tract.
  • Immune system attacks. A small number of people with chronic lymphocytic leukemia may develop an immune system reaction that causes the disease-fighting cells of the immune system to mistakenly attack the red blood cells. This is called autoimmune hemolytic anemia. The immune system also may attack the blood cells that help blood clot, called platelets. This attack is called autoimmune thrombocytopenia.
By Mayo Clinic Staff