Leukemia (leukaemia in Commonwealth English) is a cancer of the blood or bone marrow characterized by an abnormal proliferation of white blood cells (leukocytes). more...
The word leukemia refers to a group of cancers which affect the white blood cells. In the 19th century, it was seen as one single, homogenous deadly disease, characterized by a white (leuko-) appearance of blood samples. Leukemia was first recognized by the German pathologist Rudolf Virchow in 1847 and the first case was described by British pathologist John Hughes Bennett in 1845.
Leukemia arises in the bone marrow. The bone marrow produces three major types of blood cells.
- Red blood cells contain hemoglobin and are responsible for carrying oxygen to the body.
- White blood cells are responsible for fighting infection.
- Platelets assist with blood clotting.
Leukemia is characterised by an excessive production of abnormal white blood cells, overcrowding the bone marrow and often spilling out into the peripheral blood. The infiltration of the bone marrow results in decreased production and function of normal blood cells. Leukemia, dependent on the type, can spread to the lymph nodes, spleen, liver, central nervous system and other organs or tissues, causing the affected area to swell.
Damage to the bone marrow results in a lack of blood platelets, which are important in the blood clotting process. This means people with leukemia may become bruised, bleed excessively, or develop pinprick bleeds (petechiae).
White blood cells, which are involved in fighting pathogens, may be suppressed or dysfunctional, putting the patient at risk of infection.
Finally, the red blood cell deficiency leads to anemia, which may cause shortness of breath and fatigue. Bone or joint pain may occur because of cancer spreading to these areas. Headaches and vomiting are indicative of the cancer having disseminated to the central nervous system.
Enlarged lymph nodes or splenomegaly (an enlarged spleen) may occur in some types. All symptoms may also be attributable to other diseases; for diagnosis, blood tests and a bone marrow biopsy are required.
Some other related symptoms:
- Fever, chills, and other flu-like symptoms;
- Weakness and fatigue;
- Loss of appetite and/or weight;
- Swollen or bleeding gums;
- Sweating, especially at night;
- Bone or joint pain.
- Neurological symptoms (headache, paralysis, seizures) due to involvement of the brain (acute leukemias)
- Skin symptoms
Four major types
Leukemia is a broad term covering a spectrum of diseases.
Acute vs. chronic
Leukemia is clinically and pathologically split in to its acute and chronic forms.
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