Hairy Cell Leukemia is an aspect or type of Leukemia that rarely occurs and in many cases the outcome after treatment is often successful. It is not classified as one of the 4 main types of leukemia.

The word “Leukemia” is a general word for a grouping of similar cancers.

Often Hairy cell leukemia (HCL) may find itself classified as a type of Chronic Lymphoid Leukemia

On a cellular level this cancer is a cancer of mature B cells. These B cells are involved in the immune response of the body. The main function of B Cells is the production of antibodies and antigens. Over time these cells develop into memory B cells which help the body adapt and protect against a viral, bacterial or other attacks.

The concern for HCL is found in the bone marrow where groupings of “hairy cells” and “reticulin fibrosis” point towards a cancer pathology.

Hairy cells are B cells that are considered unhealthy!! As a result, they produce a  protein called Interleukin-2 receptors. This causes a large amount of hairy cells and a low amount of the necessary Bone Marrow Cells.

It is then observed that the bone marrow itself then can “fail”. Hairy Cell Leukemia was previously known as leukemic reticuloendotheliosis


–  Prone to infections
–  Fatigue
–  Malaise
–  Increased bleeding
–  Enlargement of Spleen

Possible Causes:

–  Overall cause is unknown
–  Possible Genetics
–  Possible Outside Source

Classifications of Hairy Cell Leukemia

Classic or Hairy Cell leukemia or HCL

2.)  Variant or HCL-V – 2 types


1.)  Hairy Cell leukemia –  Japanese Variant

–  Often seen in men

2.) Non Japanese Variant

–  Usually is more difficult to treat


1.)  Blood work is essential
. Low platelets
. Low white blood cells
. Low red blood cells
. Hairy cells in blood – most important findings on blood work

2.)  Bone Marrow Biopsy

3.)  Flow cytometry blood test
– Can identify cancer cells


–  Not everyone needs treatment – at least not initially
–  One type of drug may be the treatment of choice.


Purine analog

**** – both are first line treatment regimens

*** –   95 % respond to treatment with 85% getting complete remission

Monoclonal antibodies

.  Rituximab  –  main secondary treatment option
. Ibritumomab tiuxetan

– hormone for the immune system that is given to a small amount of individuals

Removal of the Spleen

Bone marrow transplants – very rare in this case