As stated earlier, laboratory diagnosis begins with finding immature cells on the peripheral blood smear. If blasts are seen, the next step would be to characterize the lineage of the blasts.
Bone marrow biopsies and smears are then obtained. If blasts are 20% or greater in the bone marrow and/or peripheral blood, presumptive acute leukemia can be determined.
Additional steps that can be taken:
- Further morphologic evaluation
- Cytochemical staining
- Conventional cytogenetic analysis
- Appropriate molecular genetic and/or FISH studies
- Obtaining possible CSF sample, skin or other biopsies, depending on patient's clinical situation
Steps 1 and 2 were discussed earlier in the sections on "differentiation between myeloid and lymphoid lines" and "distinguishing between acute or chronic leukemia".
Steps 3 and 4 will be discussed in the following pages.
