Leukemias

Leukemias

Acute leukemia
It is defined pathologically as blast cells leukemia or malignancy of immature hemopoeitic cells.
Bone marrow shows more than 30% blast cells.
They are classified into two types; acute myeloblastic leukemia (AML) and acute lymphoblastic leukemia (ALL).
The different types of blast cells are recognized by:
1. Morphology.
2. Cytochemical stain.
3. Immunological markers (MC antibodies).
4. Cytogenetic.
5. Molecular biology techniques.
6. Rarely electron microscopy.

** In childhood leukemia (age less than 15 years), ALL constitutes 80% of them; while in adulthood leukemia (age more than 15 years), AML constitutes 80% of them.

Causes of acute leukemia:
Mostly unknown; but a number of environmental agents have been implicated as inducers of certain types of leukemia, e.g.:
1. Ionizing radiation: Atomic bomb explosion in Hiroshima.
2. Chemical carcinogens: Benzene in shoes factory and alkylating agents used to treat other malignancies.
3. Genetic disorders: Down syndrome and Fanconi s syndrome.
4. Acquired disorders: Myelodysplastic syndrome, aplastic anemia, chemotherapy and radiotherapy.
5. Chromosomal and oncogen abnormalities.