Hairy Cell Leukemia

At a Glance

  • Hairy cell leukemia is a rare blood disorder cancer of the blood and bone marrow.
  • The disease is called hairy cell leukemia because the leukemia cells look “hairy” when viewed under a microscope.
  • Hairy cell leukemia either gets worse slowly or does not get worse at all.
  • It has an excellent survival rate because of a new and relatively non-toxic treatment. The majority of cases experience complete remission and live more than ten years after diagnosis.
What Is Hairy Cell Leukemia? Hairy cell leukemia is a rare cancer of the blood and bone marrow in which the bone marrow makes too many lymphocytes, a type of white blood cell. Normally, the bone marrow makes blood stem cells (immature cells) that develop into mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell. The myeloid stem cell develops into one of three types of mature blood cells:
  • Red blood cells that carry oxygen and other materials to all tissues of the body.
  • White blood cells that fight infection and disease.
  • Platelets that help prevent bleeding by causing blood clots to form.
The lymphoid stem cell develops into a lymphoblast cell and then into one of three types of lymphocytes (white blood cells):
  • B lymphocytes that make antibodies to help fight infection.
  • T lymphocytes that help B lymphocytes make antibodies to help fight infection.
  • Natural killer cells that attack cancer cells and viruses.
In hairy cell leukemia, too many blood stem cells develop into lymphocytes. These lymphocytes are abnormal and do not become healthy white blood cells. They may also be called leukemic cells. The leukemic cells can build up in the blood and bone marrow so there is less room for healthy white blood cells, red blood cells, and platelets. This may cause infection, anemia, and easy bleeding. Some of the leukemia cells may collect in the spleen and cause it to swell.

Risk Factors

Anything that increases your chance of getting a disease is called a risk factor. Gender and age may affect the risk of developing hairy cell leukemia. It occurs more often in older men.


Possible signs of hairy cell leukemia include:
  • Weakness or feeling tired.
  • Fever or frequent infections.
  • Easy bruising or bleeding.
  • Shortness of breath.
  • Weight loss for no known reason.
  • Pain or a feeling of fullness below the ribs.
  • Painless lumps in the neck, underarm, stomach, or groin.
If you have symptoms, increased risk factors or have recently been diagnosed with hairy cell leukemia, contact us to request an appointment with Diablo Valley Oncology’s physicians. We offer clinical trials for hematologic malignancies.