Blood cells are produced in the bone marrow, a spongy material found inside bones. The bone marrow contains stem cells which mature to become either myeloid cells or lymphoid cells. The myeloid cell include red blood cells, white blood cells and platelets, while the lymphoid cells can be divided into the B lymphocytes, the T lymphocytes and natural killer cells.
These stem cells are therefore responsible for creating the red blood cells that transport oxygen to various parts of the body as well as the white blood cells that fight off infection and the platelets that aid clotting and prevent bleeding. In leukemia, cancer originates in the stem cells in the bone marrow, which then fails to release normal, mature blood cells and instead releases an increased number of immature white blood cells known of as blast cells. In hairy cell leukemia, the abnormal white blood cells are characterized by surrounding fine, hair-like projections on microscopic examination.
The increased number of abnormal white blood cells eventually disrupts the normal balance of blood cells. A leukemia patient becomes deficient in red blood cells and platelets meaning their blood’s ability to transport oxygen around the body is compromised as well as its ability to clot when an injury occurs. The white blood cells develop abnormally, meaning the patient is susceptible to infection. The accumulation of abnormal white blood cells also leads to an enlarged spleen, which can cause a sore lump in the left side of the abdomen.
Risk factors for hairy cell leukemia
The cause of hairy cell leukemia is not well understood and exposure to harmful substances such as tobacco, ionizing radiation or toxic chemicals does not seem to increase the risk of this type of leukemia.
Reviewed by Sally Robertson, BSc