Acute Lymphoblastic Leukemia (ALL) is a cancer in which immature white blood cells overgrow in the blood and bone marrow space. ALL is a common form of leukemia in children but is responsible for only 20% of adult acute leukemias.
Patients present with complaints that resemble those seen in acute myelogenous leukemia (AML). These include fatigue, fever, night sweats, easy bruising or unusual bleeding, since both conditions interfere with the production of the normal blood components (red cells, white cells and platelets).
Classification of ALL
ALL is assessed by the white blood cell count at diagnosis and the chromosomal content of the leukemia cells since these features are helpful in predicting the success rate of standard therapy.
A number of chromosomal abnormalities are known to predict a below average outcome with standard ALL chemotherapy. These are:
The "Philadelphia chromosome" which is a "translocation" between chromosomes 9 and 22.
A "translocation" between chromosomes 4 and 11
Less than the normal 46 chromosomes
Sometimes the leukemia cells have features of both ALL and AML. This is referred to as Acute Biphenotypic Leukemia (ABL). On the other hand, if the leukemia cells lack any distinguishing features of ALL or AML, the disease is referred to as Acute Undifferentiated Leukemia (AUL). Although both ABL and AUL are rare (less than 5% of adult acute leukemias), they do not respond well to standard chemotherapy.
In ALL, the white cell count at diagnosis, the chromosomal changes in the leukemia cells and the initial response to therapy all determine the specific treatment recommended for the individual patient.
The following web sites may provide further helpful information: