Hairy cell leukemia

Definition

Hairy cell leukemia is a chronic leukemia characterized by the presence of so-called hairy cells. Hairy cells are characterized by the appearance of mononuclear cells with fine hair protrusions of cytoplasm on the cell surface and the presence of tartrate-resistant acid phosphatase in the cytoplasm. Their non-tumor equivalent is not known (previously was considered origin from endothelium - the older name for the disease was leukemic reticuloendotheliosis, today they are considered atypical B-lymphocytes (rarely they can also originate from T-lymphocytes)). This leukemia is classified as Non-Hodgkin's lymphoma with low malignancy, they have some properties of macrophages (ability of Phagocytosis) and of lymphocytes (they carry surface Antibodies and react with monoclonal antibodies against B-lymphocytes). Occurs in adults, especially in men.

Hairy cell leukemia

Microscopic findings

Bone marrow

• Massive infiltration of networked lymphoid and monocytic cells,
• original hematopoesis is supressed, number of mastocytes and reticular fibers is increased,
• massive infiltration of bone marrow does not correlate with blood count.

Extramedullary tissues

1. Spleen – diffuse infiltration, lymphocytes increase the size of red pulp (so-called angiomatoid transformation of the spleen),
2. Liver – tumorous infiltration less marcant than in spleen,
3. nodes – usually no infiltration.

References

Related articles

• Leukemia
• Acute lymphocytic leukemia
• Acute myeloid leukemia
• Chronic myeloid leukemia
• Chronic lymphocytic leukemia

Source

• PASTOR, Jan. Langenbeck's medical web page [online]. ©2006. [cit. 30.9.2010]. <http://langenbeck.webs.com/pathologie.htm>.