Changes

==Types==

==Types==

Leukemias are differentiated by the type of white blood cell involved, and the speed at which they develop.  

Leukemias are differentiated by the type of white blood cell involved, and the speed at which they develop. Myeloid leukemias are derived from blasts in the myeloid linage (producing macrophages, granuloctes), whereas lymphoid or lymphoblastic leukemias are derived from blasts in the lymphoid linage (producing B, T and NK lymphoid cells). Acute leukemias develop over a period of weeks to a couple of months, and are rapidly fatal if untrated. Chronic leukemias develop over years, and can generally be treated with supportive treatment and single agent chemotherapies. Chronic leukemias have the risk of undergoing a transformation to an acute leukemia, known as an acute blast crisis.

The four most common types of leukemia are:

The four most common types of leukemia are:

==Symptoms==

==Symptoms==

The effects of leukemias are due to the displacement of normal cell linages in the bone marrow, and the involvement of other organs. These include:

The effects of leukemias are due to the displacement of normal cell linages in the bone marrow, and the infiltration of other organs. These include:

** anaemia - a deficiency in red blood cells, reducing the oxygen carrying capacity of the blood producing lethargy, and increasing the risk of hypoxic events (such as acute coronary syndrome)

* anaemia - a deficiency in red blood cells, reducing the oxygen carrying capacity of the blood producing lethargy, and increasing the risk of hypoxic events (such as acute coronary syndrome)

** leukipenia - a deficiency in white blood cells, reducing the body's ability to fight infection

* leukipenia - a deficiency in white blood cells, reducing the body's ability to fight infection

** thrombocytopenia - a deficiency in platelets, increasing the risk of bleeds; less common than the others

* thrombocytopenia - a deficiency in platelets, increasing the risk of bleeds; less common than the others

** lymphadenopathy - due to involvement of the lymph nodes

* lymphadenopathy - due to involvement of the lymph nodes

** hypersplenism - due to the breakdown of blasts, can cause sequestration of normal cells and increases the risk of disseminated intravascular coagulopathy (a clotting disorder)

* hypersplenism - due to the breakdown of blasts, can cause sequestration of normal cells and increases the risk of disseminated intravascular coagulopathy (a clotting disorder)

** boney involvement - causing bone pain

* boney involvement - causing bone pain and pathological fractures (more common in other malignancies)

**  

* leukemic cutis - skin lesions, often not problematic in themselves but a marker of the disease

 

* leptomeningeal disease - infiltration of the meninges surrounding the brain, can cause a mass effect resulting in focal neurological deficiencies and, if untreated, herniation

==Treatment==

==Treatment==

The mainstay of treatment for leukemia is chemotherapy. Cytotoxic agents are introduced into the body according to strict protocols. These affect rapidly dividing cells, including not only leukemia cells, but also normal blood cells, hair, and the mucosal surfaces lining the gastrointestinal tract.  

The mainstay of treatment for leukemia is chemotherapy. Cytotoxic agents are introduced into the body according to strict protocols. These affect rapidly dividing cells, including not only leukemia cells, but also normal blood cells, hair, and the mucosal surfaces lining the gastrointestinal tract.  

==Prognosis==

==Prognosis==