Large Granular Leukemia

Large granular leukemia (LGL) is a chronic leukemia related to the body’s T cells, or "natural killer cells," that normally attack tumors.


As the lymphocytes increase, they suppress healthy cells, resulting in low blood counts. As the number of oxygen-carrying red blood cells decline, patients may develop anemia, appearing pale, tired, or short of breath. A decline in platelets that normally help the blood clot may lead to easy bruising or bleeding. A decline in white blood cells puts patients at increased risk for infections that can sometimes be life-threatening.

Other symptoms include fever, night sweats, unintended weight loss, enlargement of the spleen (25–50% of patients) and in rare cases, enlargement of the liver and swollen lymph nodes.


After blood tests and a physical exam, this disease is confirmed through a biopsy of the bone marrow. After numbing the area—usually the back of the hip—physicians insert a needle into the bone to extract the marrow cells. They then examine those cells under a microscope and test them for certain genetic changes.

LGL may also be confirmed using flow cytometric analysis of the circulating blood or bone marrow cells. During this procedure, various kinds of cells are separated, identified, and counted.

Most LGL patients have a good prognosis. LGL in the skin, bones, lymph nodes, or pituitary gland usually responds to treatment and is called low risk. High-risk disease involves the spleen, liver, bone marrow, lung, and skeleton.

Risk Factors

LGL accounts for only 2–3% of all small lymphocytic leuekemias. It is a disease of the elderly, with the average age, at diagnosis, of 60 years old. While it has been found in all age groups, including children, only 25% of patients are younger than 50 years old. Men and women are affected equally. Although the exact cause of LGL is unknown, autoimmune diseases like rheumatoid arthritis have been diagnosed before the onset of LGL in about 20% of patients.


Patients with LGL are usually monitored long term to detect late complications of the disease, including skeletal deformity or function, liver or lung problems, endocrine abnormalities, dental issues, or neurological and neurocognitive dysfunction.

Since LGL can affect so many areas of the body, it is best treated by a multidisciplinary team approach, involving hematologists (blood specialists), oncologists (cancer specialists), surgeons, pulmonologists (lung), dermatologists (skin), dentists, or endocrinologists (diabetes/hormones).

Treatment of this disease usually involves chemotherapy. It may also involved the use of a granulocyte-colony stimulating factor (G-CSF), and in some cases, surgery to remove the spleen.